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1001cb0ef41Sopenharmony_ci <button class="theme-toggle-btn" id="theme-toggle-btn" title="Toggle dark mode/light mode" aria-label="Toggle dark mode/light mode" hidden> 1011cb0ef41Sopenharmony_ci <svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" height="24" width="24"> 1021cb0ef41Sopenharmony_ci <path fill="none" d="M0 0h24v24H0z" /> 1031cb0ef41Sopenharmony_ci <path d="M11.1 12.08c-2.33-4.51-.5-8.48.53-10.07C6.27 2.2 1.98 6.59 1.98 12c0 .14.02.28.02.42.62-.27 1.29-.42 2-.42 1.66 0 3.18.83 4.1 2.15A4.01 4.01 0 0111 18c0 1.52-.87 2.83-2.12 3.51.98.32 2.03.5 3.11.5 3.5 0 6.58-1.8 8.37-4.52-2.36.23-6.98-.97-9.26-5.41z"/> 1041cb0ef41Sopenharmony_ci <path d="M7 16h-.18C6.4 14.84 5.3 14 4 14c-1.66 0-3 1.34-3 3s1.34 3 3 3h3c1.1 0 2-.9 2-2s-.9-2-2-2z"/> 1051cb0ef41Sopenharmony_ci </svg> 1061cb0ef41Sopenharmony_ci <svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" height="24" width="24"> 1071cb0ef41Sopenharmony_ci <path d="M0 0h24v24H0z" fill="none" /> 1081cb0ef41Sopenharmony_ci <path d="M6.76 4.84l-1.8-1.79-1.41 1.41 1.79 1.79 1.42-1.41zM4 10.5H1v2h3v-2zm9-9.95h-2V3.5h2V.55zm7.45 3.91l-1.41-1.41-1.79 1.79 1.41 1.41 1.79-1.79zm-3.21 13.7l1.79 1.8 1.41-1.41-1.8-1.79-1.4 1.4zM20 10.5v2h3v-2h-3zm-8-5c-3.31 0-6 2.69-6 6s2.69 6 6 6 6-2.69 6-6-2.69-6-6-6zm-1 16.95h2V19.5h-2v2.95zm-7.45-3.91l1.41 1.41 1.79-1.8-1.41-1.41-1.79 1.8z"/> 1091cb0ef41Sopenharmony_ci </svg> 1101cb0ef41Sopenharmony_ci </button> 1111cb0ef41Sopenharmony_ci </div> 1121cb0ef41Sopenharmony_ci <div id="gtoc"> 1131cb0ef41Sopenharmony_ci <ul> 1141cb0ef41Sopenharmony_ci <li class="pinned-header">Node.js v18.20.1</li> 1151cb0ef41Sopenharmony_ci 1161cb0ef41Sopenharmony_ci <li class="picker-header"> 1171cb0ef41Sopenharmony_ci <a href="#"> 1181cb0ef41Sopenharmony_ci <span class="collapsed-arrow">►</span><span class="expanded-arrow">▼</span> 1191cb0ef41Sopenharmony_ci Table of contents 1201cb0ef41Sopenharmony_ci </a> 1211cb0ef41Sopenharmony_ci 1221cb0ef41Sopenharmony_ci <div class="picker"><div class="toc"><ul> 1231cb0ef41Sopenharmony_ci<li><span class="stability_2"><a href="#dns">DNS</a></span> 1241cb0ef41Sopenharmony_ci<ul> 1251cb0ef41Sopenharmony_ci<li><a href="#class-dnsresolver">Class: <code>dns.Resolver</code></a> 1261cb0ef41Sopenharmony_ci<ul> 1271cb0ef41Sopenharmony_ci<li><a href="#resolveroptions"><code>Resolver([options])</code></a></li> 1281cb0ef41Sopenharmony_ci<li><a href="#resolvercancel"><code>resolver.cancel()</code></a></li> 1291cb0ef41Sopenharmony_ci<li><a href="#resolversetlocaladdressipv4-ipv6"><code>resolver.setLocalAddress([ipv4][, ipv6])</code></a></li> 1301cb0ef41Sopenharmony_ci</ul> 1311cb0ef41Sopenharmony_ci</li> 1321cb0ef41Sopenharmony_ci<li><a href="#dnsgetservers"><code>dns.getServers()</code></a></li> 1331cb0ef41Sopenharmony_ci<li><a href="#dnslookuphostname-options-callback"><code>dns.lookup(hostname[, options], callback)</code></a> 1341cb0ef41Sopenharmony_ci<ul> 1351cb0ef41Sopenharmony_ci<li><a href="#supported-getaddrinfo-flags">Supported getaddrinfo flags</a></li> 1361cb0ef41Sopenharmony_ci</ul> 1371cb0ef41Sopenharmony_ci</li> 1381cb0ef41Sopenharmony_ci<li><a href="#dnslookupserviceaddress-port-callback"><code>dns.lookupService(address, port, callback)</code></a></li> 1391cb0ef41Sopenharmony_ci<li><a href="#dnsresolvehostname-rrtype-callback"><code>dns.resolve(hostname[, rrtype], callback)</code></a></li> 1401cb0ef41Sopenharmony_ci<li><a href="#dnsresolve4hostname-options-callback"><code>dns.resolve4(hostname[, options], callback)</code></a></li> 1411cb0ef41Sopenharmony_ci<li><a href="#dnsresolve6hostname-options-callback"><code>dns.resolve6(hostname[, options], callback)</code></a></li> 1421cb0ef41Sopenharmony_ci<li><a href="#dnsresolveanyhostname-callback"><code>dns.resolveAny(hostname, callback)</code></a></li> 1431cb0ef41Sopenharmony_ci<li><a href="#dnsresolvecnamehostname-callback"><code>dns.resolveCname(hostname, callback)</code></a></li> 1441cb0ef41Sopenharmony_ci<li><a href="#dnsresolvecaahostname-callback"><code>dns.resolveCaa(hostname, callback)</code></a></li> 1451cb0ef41Sopenharmony_ci<li><a href="#dnsresolvemxhostname-callback"><code>dns.resolveMx(hostname, callback)</code></a></li> 1461cb0ef41Sopenharmony_ci<li><a href="#dnsresolvenaptrhostname-callback"><code>dns.resolveNaptr(hostname, callback)</code></a></li> 1471cb0ef41Sopenharmony_ci<li><a href="#dnsresolvenshostname-callback"><code>dns.resolveNs(hostname, callback)</code></a></li> 1481cb0ef41Sopenharmony_ci<li><a href="#dnsresolveptrhostname-callback"><code>dns.resolvePtr(hostname, callback)</code></a></li> 1491cb0ef41Sopenharmony_ci<li><a href="#dnsresolvesoahostname-callback"><code>dns.resolveSoa(hostname, callback)</code></a></li> 1501cb0ef41Sopenharmony_ci<li><a href="#dnsresolvesrvhostname-callback"><code>dns.resolveSrv(hostname, callback)</code></a></li> 1511cb0ef41Sopenharmony_ci<li><a href="#dnsresolvetxthostname-callback"><code>dns.resolveTxt(hostname, callback)</code></a></li> 1521cb0ef41Sopenharmony_ci<li><a href="#dnsreverseip-callback"><code>dns.reverse(ip, callback)</code></a></li> 1531cb0ef41Sopenharmony_ci<li><a href="#dnssetdefaultresultorderorder"><code>dns.setDefaultResultOrder(order)</code></a></li> 1541cb0ef41Sopenharmony_ci<li><a href="#dnsgetdefaultresultorder"><code>dns.getDefaultResultOrder()</code></a></li> 1551cb0ef41Sopenharmony_ci<li><a href="#dnssetserversservers"><code>dns.setServers(servers)</code></a></li> 1561cb0ef41Sopenharmony_ci<li><a href="#dns-promises-api">DNS promises API</a> 1571cb0ef41Sopenharmony_ci<ul> 1581cb0ef41Sopenharmony_ci<li><a href="#class-dnspromisesresolver">Class: <code>dnsPromises.Resolver</code></a></li> 1591cb0ef41Sopenharmony_ci<li><a href="#resolvercancel_1"><code>resolver.cancel()</code></a></li> 1601cb0ef41Sopenharmony_ci<li><a href="#dnspromisesgetservers"><code>dnsPromises.getServers()</code></a></li> 1611cb0ef41Sopenharmony_ci<li><a href="#dnspromiseslookuphostname-options"><code>dnsPromises.lookup(hostname[, options])</code></a></li> 1621cb0ef41Sopenharmony_ci<li><a href="#dnspromiseslookupserviceaddress-port"><code>dnsPromises.lookupService(address, port)</code></a></li> 1631cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvehostname-rrtype"><code>dnsPromises.resolve(hostname[, rrtype])</code></a></li> 1641cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolve4hostname-options"><code>dnsPromises.resolve4(hostname[, options])</code></a></li> 1651cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolve6hostname-options"><code>dnsPromises.resolve6(hostname[, options])</code></a></li> 1661cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolveanyhostname"><code>dnsPromises.resolveAny(hostname)</code></a></li> 1671cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvecaahostname"><code>dnsPromises.resolveCaa(hostname)</code></a></li> 1681cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvecnamehostname"><code>dnsPromises.resolveCname(hostname)</code></a></li> 1691cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvemxhostname"><code>dnsPromises.resolveMx(hostname)</code></a></li> 1701cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvenaptrhostname"><code>dnsPromises.resolveNaptr(hostname)</code></a></li> 1711cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvenshostname"><code>dnsPromises.resolveNs(hostname)</code></a></li> 1721cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolveptrhostname"><code>dnsPromises.resolvePtr(hostname)</code></a></li> 1731cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvesoahostname"><code>dnsPromises.resolveSoa(hostname)</code></a></li> 1741cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvesrvhostname"><code>dnsPromises.resolveSrv(hostname)</code></a></li> 1751cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvetxthostname"><code>dnsPromises.resolveTxt(hostname)</code></a></li> 1761cb0ef41Sopenharmony_ci<li><a href="#dnspromisesreverseip"><code>dnsPromises.reverse(ip)</code></a></li> 1771cb0ef41Sopenharmony_ci<li><a href="#dnspromisessetdefaultresultorderorder"><code>dnsPromises.setDefaultResultOrder(order)</code></a></li> 1781cb0ef41Sopenharmony_ci<li><a href="#dnspromisesgetdefaultresultorder"><code>dnsPromises.getDefaultResultOrder()</code></a></li> 1791cb0ef41Sopenharmony_ci<li><a href="#dnspromisessetserversservers"><code>dnsPromises.setServers(servers)</code></a></li> 1801cb0ef41Sopenharmony_ci</ul> 1811cb0ef41Sopenharmony_ci</li> 1821cb0ef41Sopenharmony_ci<li><a href="#error-codes">Error codes</a></li> 1831cb0ef41Sopenharmony_ci<li><a href="#implementation-considerations">Implementation considerations</a> 1841cb0ef41Sopenharmony_ci<ul> 1851cb0ef41Sopenharmony_ci<li><a href="#dnslookup"><code>dns.lookup()</code></a></li> 1861cb0ef41Sopenharmony_ci<li><a href="#dnsresolve-dnsresolve-and-dnsreverse"><code>dns.resolve()</code>, <code>dns.resolve*()</code>, and <code>dns.reverse()</code></a></li> 1871cb0ef41Sopenharmony_ci</ul> 1881cb0ef41Sopenharmony_ci</li> 1891cb0ef41Sopenharmony_ci</ul> 1901cb0ef41Sopenharmony_ci</li> 1911cb0ef41Sopenharmony_ci</ul></div></div> 1921cb0ef41Sopenharmony_ci </li> 1931cb0ef41Sopenharmony_ci 1941cb0ef41Sopenharmony_ci 1951cb0ef41Sopenharmony_ci <li class="picker-header"> 1961cb0ef41Sopenharmony_ci <a href="#"> 1971cb0ef41Sopenharmony_ci <span class="collapsed-arrow">►</span><span class="expanded-arrow">▼</span> 1981cb0ef41Sopenharmony_ci Index 1991cb0ef41Sopenharmony_ci </a> 2001cb0ef41Sopenharmony_ci 2011cb0ef41Sopenharmony_ci <div class="picker"><ul> 2021cb0ef41Sopenharmony_ci<li><a href="documentation.html" class="nav-documentation">About this documentation</a></li> 2031cb0ef41Sopenharmony_ci<li><a href="synopsis.html" class="nav-synopsis">Usage and example</a></li> 2041cb0ef41Sopenharmony_ci 2051cb0ef41Sopenharmony_ci <li> 2061cb0ef41Sopenharmony_ci <a href="index.html">Index</a> 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href="https://nodejs.org/docs/latest-v18.x/api/dns.html">18.x <b>LTS</b></a></li> 2891cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v17.x/api/dns.html">17.x</a></li> 2901cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v16.x/api/dns.html">16.x</a></li> 2911cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v15.x/api/dns.html">15.x</a></li> 2921cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v14.x/api/dns.html">14.x</a></li> 2931cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v13.x/api/dns.html">13.x</a></li> 2941cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v12.x/api/dns.html">12.x</a></li> 2951cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v11.x/api/dns.html">11.x</a></li> 2961cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v10.x/api/dns.html">10.x</a></li> 2971cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v9.x/api/dns.html">9.x</a></li> 2981cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v8.x/api/dns.html">8.x</a></li> 2991cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v7.x/api/dns.html">7.x</a></li> 3001cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v6.x/api/dns.html">6.x</a></li> 3011cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v5.x/api/dns.html">5.x</a></li> 3021cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v4.x/api/dns.html">4.x</a></li> 3031cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v0.12.x/api/dns.html">0.12.x</a></li> 3041cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v0.10.x/api/dns.html">0.10.x</a></li></ol></div> 3051cb0ef41Sopenharmony_ci </li> 3061cb0ef41Sopenharmony_ci 3071cb0ef41Sopenharmony_ci <li class="picker-header"> 3081cb0ef41Sopenharmony_ci <a href="#"> 3091cb0ef41Sopenharmony_ci <span class="collapsed-arrow">►</span><span class="expanded-arrow">▼</span> 3101cb0ef41Sopenharmony_ci Options 3111cb0ef41Sopenharmony_ci </a> 3121cb0ef41Sopenharmony_ci 3131cb0ef41Sopenharmony_ci <div class="picker"> 3141cb0ef41Sopenharmony_ci <ul> 3151cb0ef41Sopenharmony_ci <li> 3161cb0ef41Sopenharmony_ci <a href="all.html">View on single page</a> 3171cb0ef41Sopenharmony_ci </li> 3181cb0ef41Sopenharmony_ci <li> 3191cb0ef41Sopenharmony_ci <a href="dns.json">View as JSON</a> 3201cb0ef41Sopenharmony_ci </li> 3211cb0ef41Sopenharmony_ci <li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/main/doc/api/dns.md">Edit on GitHub</a></li> 3221cb0ef41Sopenharmony_ci </ul> 3231cb0ef41Sopenharmony_ci </div> 3241cb0ef41Sopenharmony_ci </li> 3251cb0ef41Sopenharmony_ci </ul> 3261cb0ef41Sopenharmony_ci </div> 3271cb0ef41Sopenharmony_ci <hr> 3281cb0ef41Sopenharmony_ci </header> 3291cb0ef41Sopenharmony_ci 3301cb0ef41Sopenharmony_ci <details id="toc" open><summary>Table of contents</summary><ul> 3311cb0ef41Sopenharmony_ci<li><span class="stability_2"><a href="#dns">DNS</a></span> 3321cb0ef41Sopenharmony_ci<ul> 3331cb0ef41Sopenharmony_ci<li><a href="#class-dnsresolver">Class: <code>dns.Resolver</code></a> 3341cb0ef41Sopenharmony_ci<ul> 3351cb0ef41Sopenharmony_ci<li><a href="#resolveroptions"><code>Resolver([options])</code></a></li> 3361cb0ef41Sopenharmony_ci<li><a href="#resolvercancel"><code>resolver.cancel()</code></a></li> 3371cb0ef41Sopenharmony_ci<li><a href="#resolversetlocaladdressipv4-ipv6"><code>resolver.setLocalAddress([ipv4][, ipv6])</code></a></li> 3381cb0ef41Sopenharmony_ci</ul> 3391cb0ef41Sopenharmony_ci</li> 3401cb0ef41Sopenharmony_ci<li><a href="#dnsgetservers"><code>dns.getServers()</code></a></li> 3411cb0ef41Sopenharmony_ci<li><a href="#dnslookuphostname-options-callback"><code>dns.lookup(hostname[, options], callback)</code></a> 3421cb0ef41Sopenharmony_ci<ul> 3431cb0ef41Sopenharmony_ci<li><a href="#supported-getaddrinfo-flags">Supported getaddrinfo flags</a></li> 3441cb0ef41Sopenharmony_ci</ul> 3451cb0ef41Sopenharmony_ci</li> 3461cb0ef41Sopenharmony_ci<li><a href="#dnslookupserviceaddress-port-callback"><code>dns.lookupService(address, port, callback)</code></a></li> 3471cb0ef41Sopenharmony_ci<li><a href="#dnsresolvehostname-rrtype-callback"><code>dns.resolve(hostname[, rrtype], callback)</code></a></li> 3481cb0ef41Sopenharmony_ci<li><a href="#dnsresolve4hostname-options-callback"><code>dns.resolve4(hostname[, options], callback)</code></a></li> 3491cb0ef41Sopenharmony_ci<li><a href="#dnsresolve6hostname-options-callback"><code>dns.resolve6(hostname[, options], callback)</code></a></li> 3501cb0ef41Sopenharmony_ci<li><a href="#dnsresolveanyhostname-callback"><code>dns.resolveAny(hostname, callback)</code></a></li> 3511cb0ef41Sopenharmony_ci<li><a href="#dnsresolvecnamehostname-callback"><code>dns.resolveCname(hostname, callback)</code></a></li> 3521cb0ef41Sopenharmony_ci<li><a href="#dnsresolvecaahostname-callback"><code>dns.resolveCaa(hostname, callback)</code></a></li> 3531cb0ef41Sopenharmony_ci<li><a href="#dnsresolvemxhostname-callback"><code>dns.resolveMx(hostname, callback)</code></a></li> 3541cb0ef41Sopenharmony_ci<li><a href="#dnsresolvenaptrhostname-callback"><code>dns.resolveNaptr(hostname, callback)</code></a></li> 3551cb0ef41Sopenharmony_ci<li><a href="#dnsresolvenshostname-callback"><code>dns.resolveNs(hostname, callback)</code></a></li> 3561cb0ef41Sopenharmony_ci<li><a href="#dnsresolveptrhostname-callback"><code>dns.resolvePtr(hostname, callback)</code></a></li> 3571cb0ef41Sopenharmony_ci<li><a href="#dnsresolvesoahostname-callback"><code>dns.resolveSoa(hostname, callback)</code></a></li> 3581cb0ef41Sopenharmony_ci<li><a href="#dnsresolvesrvhostname-callback"><code>dns.resolveSrv(hostname, callback)</code></a></li> 3591cb0ef41Sopenharmony_ci<li><a href="#dnsresolvetxthostname-callback"><code>dns.resolveTxt(hostname, callback)</code></a></li> 3601cb0ef41Sopenharmony_ci<li><a href="#dnsreverseip-callback"><code>dns.reverse(ip, callback)</code></a></li> 3611cb0ef41Sopenharmony_ci<li><a href="#dnssetdefaultresultorderorder"><code>dns.setDefaultResultOrder(order)</code></a></li> 3621cb0ef41Sopenharmony_ci<li><a href="#dnsgetdefaultresultorder"><code>dns.getDefaultResultOrder()</code></a></li> 3631cb0ef41Sopenharmony_ci<li><a href="#dnssetserversservers"><code>dns.setServers(servers)</code></a></li> 3641cb0ef41Sopenharmony_ci<li><a href="#dns-promises-api">DNS promises API</a> 3651cb0ef41Sopenharmony_ci<ul> 3661cb0ef41Sopenharmony_ci<li><a href="#class-dnspromisesresolver">Class: <code>dnsPromises.Resolver</code></a></li> 3671cb0ef41Sopenharmony_ci<li><a href="#resolvercancel_1"><code>resolver.cancel()</code></a></li> 3681cb0ef41Sopenharmony_ci<li><a href="#dnspromisesgetservers"><code>dnsPromises.getServers()</code></a></li> 3691cb0ef41Sopenharmony_ci<li><a href="#dnspromiseslookuphostname-options"><code>dnsPromises.lookup(hostname[, options])</code></a></li> 3701cb0ef41Sopenharmony_ci<li><a href="#dnspromiseslookupserviceaddress-port"><code>dnsPromises.lookupService(address, port)</code></a></li> 3711cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvehostname-rrtype"><code>dnsPromises.resolve(hostname[, rrtype])</code></a></li> 3721cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolve4hostname-options"><code>dnsPromises.resolve4(hostname[, options])</code></a></li> 3731cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolve6hostname-options"><code>dnsPromises.resolve6(hostname[, options])</code></a></li> 3741cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolveanyhostname"><code>dnsPromises.resolveAny(hostname)</code></a></li> 3751cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvecaahostname"><code>dnsPromises.resolveCaa(hostname)</code></a></li> 3761cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvecnamehostname"><code>dnsPromises.resolveCname(hostname)</code></a></li> 3771cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvemxhostname"><code>dnsPromises.resolveMx(hostname)</code></a></li> 3781cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvenaptrhostname"><code>dnsPromises.resolveNaptr(hostname)</code></a></li> 3791cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvenshostname"><code>dnsPromises.resolveNs(hostname)</code></a></li> 3801cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolveptrhostname"><code>dnsPromises.resolvePtr(hostname)</code></a></li> 3811cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvesoahostname"><code>dnsPromises.resolveSoa(hostname)</code></a></li> 3821cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvesrvhostname"><code>dnsPromises.resolveSrv(hostname)</code></a></li> 3831cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvetxthostname"><code>dnsPromises.resolveTxt(hostname)</code></a></li> 3841cb0ef41Sopenharmony_ci<li><a href="#dnspromisesreverseip"><code>dnsPromises.reverse(ip)</code></a></li> 3851cb0ef41Sopenharmony_ci<li><a href="#dnspromisessetdefaultresultorderorder"><code>dnsPromises.setDefaultResultOrder(order)</code></a></li> 3861cb0ef41Sopenharmony_ci<li><a href="#dnspromisesgetdefaultresultorder"><code>dnsPromises.getDefaultResultOrder()</code></a></li> 3871cb0ef41Sopenharmony_ci<li><a href="#dnspromisessetserversservers"><code>dnsPromises.setServers(servers)</code></a></li> 3881cb0ef41Sopenharmony_ci</ul> 3891cb0ef41Sopenharmony_ci</li> 3901cb0ef41Sopenharmony_ci<li><a href="#error-codes">Error codes</a></li> 3911cb0ef41Sopenharmony_ci<li><a href="#implementation-considerations">Implementation considerations</a> 3921cb0ef41Sopenharmony_ci<ul> 3931cb0ef41Sopenharmony_ci<li><a href="#dnslookup"><code>dns.lookup()</code></a></li> 3941cb0ef41Sopenharmony_ci<li><a href="#dnsresolve-dnsresolve-and-dnsreverse"><code>dns.resolve()</code>, <code>dns.resolve*()</code>, and <code>dns.reverse()</code></a></li> 3951cb0ef41Sopenharmony_ci</ul> 3961cb0ef41Sopenharmony_ci</li> 3971cb0ef41Sopenharmony_ci</ul> 3981cb0ef41Sopenharmony_ci</li> 3991cb0ef41Sopenharmony_ci</ul></details> 4001cb0ef41Sopenharmony_ci 4011cb0ef41Sopenharmony_ci <div id="apicontent"> 4021cb0ef41Sopenharmony_ci <h2>DNS<span><a class="mark" href="#dns" id="dns">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns"></a></h2> 4031cb0ef41Sopenharmony_ci 4041cb0ef41Sopenharmony_ci<p></p><div class="api_stability api_stability_2"><a href="documentation.html#stability-index">Stability: 2</a> - Stable</div><p></p> 4051cb0ef41Sopenharmony_ci<p><strong>Source Code:</strong> <a href="https://github.com/nodejs/node/blob/v18.20.1/lib/dns.js">lib/dns.js</a></p> 4061cb0ef41Sopenharmony_ci<p>The <code>node:dns</code> module enables name resolution. For example, use it to look up IP 4071cb0ef41Sopenharmony_ciaddresses of host names.</p> 4081cb0ef41Sopenharmony_ci<p>Although named for the <a href="https://en.wikipedia.org/wiki/Domain_Name_System">Domain Name System (DNS)</a>, it does not always use the 4091cb0ef41Sopenharmony_ciDNS protocol for lookups. <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> uses the operating system 4101cb0ef41Sopenharmony_cifacilities to perform name resolution. It may not need to perform any network 4111cb0ef41Sopenharmony_cicommunication. To perform name resolution the way other applications on the same 4121cb0ef41Sopenharmony_cisystem do, use <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a>.</p> 4131cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> dns = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>); 4141cb0ef41Sopenharmony_ci 4151cb0ef41Sopenharmony_cidns.<span class="hljs-title function_">lookup</span>(<span class="hljs-string">'example.org'</span>, <span class="hljs-function">(<span class="hljs-params">err, address, family</span>) =></span> { 4161cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'address: %j family: IPv%s'</span>, address, family); 4171cb0ef41Sopenharmony_ci}); 4181cb0ef41Sopenharmony_ci<span class="hljs-comment">// address: "93.184.216.34" family: IPv4</span></code> <button class="copy-button">copy</button></pre> 4191cb0ef41Sopenharmony_ci<p>All other functions in the <code>node:dns</code> module connect to an actual DNS server to 4201cb0ef41Sopenharmony_ciperform name resolution. They will always use the network to perform DNS 4211cb0ef41Sopenharmony_ciqueries. These functions do not use the same set of configuration files used by 4221cb0ef41Sopenharmony_ci<a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> (e.g. <code>/etc/hosts</code>). Use these functions to always perform 4231cb0ef41Sopenharmony_ciDNS queries, bypassing other name-resolution facilities.</p> 4241cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> dns = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>); 4251cb0ef41Sopenharmony_ci 4261cb0ef41Sopenharmony_cidns.<span class="hljs-title function_">resolve4</span>(<span class="hljs-string">'archive.org'</span>, <span class="hljs-function">(<span class="hljs-params">err, addresses</span>) =></span> { 4271cb0ef41Sopenharmony_ci <span class="hljs-keyword">if</span> (err) <span class="hljs-keyword">throw</span> err; 4281cb0ef41Sopenharmony_ci 4291cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">`addresses: <span class="hljs-subst">${<span class="hljs-built_in">JSON</span>.stringify(addresses)}</span>`</span>); 4301cb0ef41Sopenharmony_ci 4311cb0ef41Sopenharmony_ci addresses.<span class="hljs-title function_">forEach</span>(<span class="hljs-function">(<span class="hljs-params">a</span>) =></span> { 4321cb0ef41Sopenharmony_ci dns.<span class="hljs-title function_">reverse</span>(a, <span class="hljs-function">(<span class="hljs-params">err, hostnames</span>) =></span> { 4331cb0ef41Sopenharmony_ci <span class="hljs-keyword">if</span> (err) { 4341cb0ef41Sopenharmony_ci <span class="hljs-keyword">throw</span> err; 4351cb0ef41Sopenharmony_ci } 4361cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">`reverse for <span class="hljs-subst">${a}</span>: <span class="hljs-subst">${<span class="hljs-built_in">JSON</span>.stringify(hostnames)}</span>`</span>); 4371cb0ef41Sopenharmony_ci }); 4381cb0ef41Sopenharmony_ci }); 4391cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre> 4401cb0ef41Sopenharmony_ci<p>See the <a href="#implementation-considerations">Implementation considerations section</a> for more information.</p> 4411cb0ef41Sopenharmony_ci<section><h3>Class: <code>dns.Resolver</code><span><a class="mark" href="#class-dnsresolver" id="class-dnsresolver">#</a></span><a aria-hidden="true" class="legacy" id="dns_class_dns_resolver"></a></h3> 4421cb0ef41Sopenharmony_ci<div class="api_metadata"> 4431cb0ef41Sopenharmony_ci<span>Added in: v8.3.0</span> 4441cb0ef41Sopenharmony_ci</div> 4451cb0ef41Sopenharmony_ci<p>An independent resolver for DNS requests.</p> 4461cb0ef41Sopenharmony_ci<p>Creating a new resolver uses the default server settings. Setting 4471cb0ef41Sopenharmony_cithe servers used for a resolver using 4481cb0ef41Sopenharmony_ci<a href="#dnssetserversservers"><code>resolver.setServers()</code></a> does not affect 4491cb0ef41Sopenharmony_ciother resolvers:</p> 4501cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> { <span class="hljs-title class_">Resolver</span> } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>); 4511cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> resolver = <span class="hljs-keyword">new</span> <span class="hljs-title class_">Resolver</span>(); 4521cb0ef41Sopenharmony_ciresolver.<span class="hljs-title function_">setServers</span>([<span class="hljs-string">'4.4.4.4'</span>]); 4531cb0ef41Sopenharmony_ci 4541cb0ef41Sopenharmony_ci<span class="hljs-comment">// This request will use the server at 4.4.4.4, independent of global settings.</span> 4551cb0ef41Sopenharmony_ciresolver.<span class="hljs-title function_">resolve4</span>(<span class="hljs-string">'example.org'</span>, <span class="hljs-function">(<span class="hljs-params">err, addresses</span>) =></span> { 4561cb0ef41Sopenharmony_ci <span class="hljs-comment">// ...</span> 4571cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre> 4581cb0ef41Sopenharmony_ci<p>The following methods from the <code>node:dns</code> module are available:</p> 4591cb0ef41Sopenharmony_ci<ul> 4601cb0ef41Sopenharmony_ci<li><a href="#dnsgetservers"><code>resolver.getServers()</code></a></li> 4611cb0ef41Sopenharmony_ci<li><a href="#dnsresolvehostname-rrtype-callback"><code>resolver.resolve()</code></a></li> 4621cb0ef41Sopenharmony_ci<li><a href="#dnsresolve4hostname-options-callback"><code>resolver.resolve4()</code></a></li> 4631cb0ef41Sopenharmony_ci<li><a href="#dnsresolve6hostname-options-callback"><code>resolver.resolve6()</code></a></li> 4641cb0ef41Sopenharmony_ci<li><a href="#dnsresolveanyhostname-callback"><code>resolver.resolveAny()</code></a></li> 4651cb0ef41Sopenharmony_ci<li><a href="#dnsresolvecaahostname-callback"><code>resolver.resolveCaa()</code></a></li> 4661cb0ef41Sopenharmony_ci<li><a href="#dnsresolvecnamehostname-callback"><code>resolver.resolveCname()</code></a></li> 4671cb0ef41Sopenharmony_ci<li><a href="#dnsresolvemxhostname-callback"><code>resolver.resolveMx()</code></a></li> 4681cb0ef41Sopenharmony_ci<li><a href="#dnsresolvenaptrhostname-callback"><code>resolver.resolveNaptr()</code></a></li> 4691cb0ef41Sopenharmony_ci<li><a href="#dnsresolvenshostname-callback"><code>resolver.resolveNs()</code></a></li> 4701cb0ef41Sopenharmony_ci<li><a href="#dnsresolveptrhostname-callback"><code>resolver.resolvePtr()</code></a></li> 4711cb0ef41Sopenharmony_ci<li><a href="#dnsresolvesoahostname-callback"><code>resolver.resolveSoa()</code></a></li> 4721cb0ef41Sopenharmony_ci<li><a href="#dnsresolvesrvhostname-callback"><code>resolver.resolveSrv()</code></a></li> 4731cb0ef41Sopenharmony_ci<li><a href="#dnsresolvetxthostname-callback"><code>resolver.resolveTxt()</code></a></li> 4741cb0ef41Sopenharmony_ci<li><a href="#dnsreverseip-callback"><code>resolver.reverse()</code></a></li> 4751cb0ef41Sopenharmony_ci<li><a href="#dnssetserversservers"><code>resolver.setServers()</code></a></li> 4761cb0ef41Sopenharmony_ci</ul> 4771cb0ef41Sopenharmony_ci<h4><code>Resolver([options])</code><span><a class="mark" href="#resolveroptions" id="resolveroptions">#</a></span><a aria-hidden="true" class="legacy" id="dns_resolver_options"></a></h4> 4781cb0ef41Sopenharmony_ci<div class="api_metadata"> 4791cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 4801cb0ef41Sopenharmony_ci<table> 4811cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 4821cb0ef41Sopenharmony_ci<tr><td>v16.7.0, v14.18.0</td> 4831cb0ef41Sopenharmony_ci<td><p>The <code>options</code> object now accepts a <code>tries</code> option.</p></td></tr> 4841cb0ef41Sopenharmony_ci<tr><td>v12.18.3</td> 4851cb0ef41Sopenharmony_ci<td><p>The constructor now accepts an <code>options</code> object. The single supported option is <code>timeout</code>.</p></td></tr> 4861cb0ef41Sopenharmony_ci<tr><td>v8.3.0</td> 4871cb0ef41Sopenharmony_ci<td><p><span>Added in: v8.3.0</span></p></td></tr> 4881cb0ef41Sopenharmony_ci</tbody></table> 4891cb0ef41Sopenharmony_ci</details> 4901cb0ef41Sopenharmony_ci</div> 4911cb0ef41Sopenharmony_ci<p>Create a new resolver.</p> 4921cb0ef41Sopenharmony_ci<ul> 4931cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 4941cb0ef41Sopenharmony_ci<ul> 4951cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Query timeout in milliseconds, or <code>-1</code> to use the 4961cb0ef41Sopenharmony_cidefault timeout.</li> 4971cb0ef41Sopenharmony_ci<li><code>tries</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The number of tries the resolver will try contacting 4981cb0ef41Sopenharmony_cieach name server before giving up. <strong>Default:</strong> <code>4</code></li> 4991cb0ef41Sopenharmony_ci</ul> 5001cb0ef41Sopenharmony_ci</li> 5011cb0ef41Sopenharmony_ci</ul> 5021cb0ef41Sopenharmony_ci<h4><code>resolver.cancel()</code><span><a class="mark" href="#resolvercancel" id="resolvercancel">#</a></span><a aria-hidden="true" class="legacy" id="dns_resolver_cancel"></a></h4> 5031cb0ef41Sopenharmony_ci<div class="api_metadata"> 5041cb0ef41Sopenharmony_ci<span>Added in: v8.3.0</span> 5051cb0ef41Sopenharmony_ci</div> 5061cb0ef41Sopenharmony_ci<p>Cancel all outstanding DNS queries made by this resolver. The corresponding 5071cb0ef41Sopenharmony_cicallbacks will be called with an error with code <code>ECANCELLED</code>.</p> 5081cb0ef41Sopenharmony_ci<h4><code>resolver.setLocalAddress([ipv4][, ipv6])</code><span><a class="mark" href="#resolversetlocaladdressipv4-ipv6" id="resolversetlocaladdressipv4-ipv6">#</a></span><a aria-hidden="true" class="legacy" id="dns_resolver_setlocaladdress_ipv4_ipv6"></a></h4> 5091cb0ef41Sopenharmony_ci<div class="api_metadata"> 5101cb0ef41Sopenharmony_ci<span>Added in: v15.1.0, v14.17.0</span> 5111cb0ef41Sopenharmony_ci</div> 5121cb0ef41Sopenharmony_ci<ul> 5131cb0ef41Sopenharmony_ci<li><code>ipv4</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> A string representation of an IPv4 address. 5141cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>'0.0.0.0'</code></li> 5151cb0ef41Sopenharmony_ci<li><code>ipv6</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> A string representation of an IPv6 address. 5161cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>'::0'</code></li> 5171cb0ef41Sopenharmony_ci</ul> 5181cb0ef41Sopenharmony_ci<p>The resolver instance will send its requests from the specified IP address. 5191cb0ef41Sopenharmony_ciThis allows programs to specify outbound interfaces when used on multi-homed 5201cb0ef41Sopenharmony_cisystems.</p> 5211cb0ef41Sopenharmony_ci<p>If a v4 or v6 address is not specified, it is set to the default and the 5221cb0ef41Sopenharmony_cioperating system will choose a local address automatically.</p> 5231cb0ef41Sopenharmony_ci<p>The resolver will use the v4 local address when making requests to IPv4 DNS 5241cb0ef41Sopenharmony_ciservers, and the v6 local address when making requests to IPv6 DNS servers. 5251cb0ef41Sopenharmony_ciThe <code>rrtype</code> of resolution requests has no impact on the local address used.</p> 5261cb0ef41Sopenharmony_ci</section><section><h3><code>dns.getServers()</code><span><a class="mark" href="#dnsgetservers" id="dnsgetservers">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_getservers"></a></h3> 5271cb0ef41Sopenharmony_ci<div class="api_metadata"> 5281cb0ef41Sopenharmony_ci<span>Added in: v0.11.3</span> 5291cb0ef41Sopenharmony_ci</div> 5301cb0ef41Sopenharmony_ci<ul> 5311cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></li> 5321cb0ef41Sopenharmony_ci</ul> 5331cb0ef41Sopenharmony_ci<p>Returns an array of IP address strings, formatted according to <a href="https://tools.ietf.org/html/rfc5952#section-6">RFC 5952</a>, 5341cb0ef41Sopenharmony_cithat are currently configured for DNS resolution. A string will include a port 5351cb0ef41Sopenharmony_cisection if a custom port is used.</p> 5361cb0ef41Sopenharmony_ci<!-- eslint-disable semi--> 5371cb0ef41Sopenharmony_ci<pre><code class="language-js">[ 5381cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4'</span>, 5391cb0ef41Sopenharmony_ci <span class="hljs-string">'2001:4860:4860::8888'</span>, 5401cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4:1053'</span>, 5411cb0ef41Sopenharmony_ci <span class="hljs-string">'[2001:4860:4860::8888]:1053'</span>, 5421cb0ef41Sopenharmony_ci]</code> <button class="copy-button">copy</button></pre> 5431cb0ef41Sopenharmony_ci</section><section><h3><code>dns.lookup(hostname[, options], callback)</code><span><a class="mark" href="#dnslookuphostname-options-callback" id="dnslookuphostname-options-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_lookup_hostname_options_callback"></a></h3> 5441cb0ef41Sopenharmony_ci<div class="api_metadata"> 5451cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 5461cb0ef41Sopenharmony_ci<table> 5471cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 5481cb0ef41Sopenharmony_ci<tr><td>v18.4.0</td> 5491cb0ef41Sopenharmony_ci<td><p>For compatibility with <code>node:net</code>, when passing an option object the <code>family</code> option can be the string <code>'IPv4'</code> or the string <code>'IPv6'</code>.</p></td></tr> 5501cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 5511cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 5521cb0ef41Sopenharmony_ci<tr><td>v17.0.0</td> 5531cb0ef41Sopenharmony_ci<td><p>The <code>verbatim</code> options defaults to <code>true</code> now.</p></td></tr> 5541cb0ef41Sopenharmony_ci<tr><td>v8.5.0</td> 5551cb0ef41Sopenharmony_ci<td><p>The <code>verbatim</code> option is supported now.</p></td></tr> 5561cb0ef41Sopenharmony_ci<tr><td>v1.2.0</td> 5571cb0ef41Sopenharmony_ci<td><p>The <code>all</code> option is supported now.</p></td></tr> 5581cb0ef41Sopenharmony_ci<tr><td>v0.1.90</td> 5591cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.90</span></p></td></tr> 5601cb0ef41Sopenharmony_ci</tbody></table> 5611cb0ef41Sopenharmony_ci</details> 5621cb0ef41Sopenharmony_ci</div> 5631cb0ef41Sopenharmony_ci<ul> 5641cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 5651cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 5661cb0ef41Sopenharmony_ci<ul> 5671cb0ef41Sopenharmony_ci<li><code>family</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The record family. Must be <code>4</code>, <code>6</code>, or <code>0</code>. For 5681cb0ef41Sopenharmony_cibackward compatibility reasons,<code>'IPv4'</code> and <code>'IPv6'</code> are interpreted as <code>4</code> 5691cb0ef41Sopenharmony_ciand <code>6</code> respectively. The value <code>0</code> indicates that IPv4 and IPv6 addresses 5701cb0ef41Sopenharmony_ciare both returned. <strong>Default:</strong> <code>0</code>.</li> 5711cb0ef41Sopenharmony_ci<li><code>hints</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> One or more <a href="#supported-getaddrinfo-flags">supported <code>getaddrinfo</code> flags</a>. Multiple 5721cb0ef41Sopenharmony_ciflags may be passed by bitwise <code>OR</code>ing their values.</li> 5731cb0ef41Sopenharmony_ci<li><code>all</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> When <code>true</code>, the callback returns all resolved addresses in 5741cb0ef41Sopenharmony_cian array. Otherwise, returns a single address. <strong>Default:</strong> <code>false</code>.</li> 5751cb0ef41Sopenharmony_ci<li><code>verbatim</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> When <code>true</code>, the callback receives IPv4 and IPv6 5761cb0ef41Sopenharmony_ciaddresses in the order the DNS resolver returned them. When <code>false</code>, 5771cb0ef41Sopenharmony_ciIPv4 addresses are placed before IPv6 addresses. 5781cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>true</code> (addresses are not reordered). Default value is 5791cb0ef41Sopenharmony_ciconfigurable using <a href="#dnssetdefaultresultorderorder"><code>dns.setDefaultResultOrder()</code></a> or 5801cb0ef41Sopenharmony_ci<a href="cli.html#--dns-result-orderorder"><code>--dns-result-order</code></a>.</li> 5811cb0ef41Sopenharmony_ci</ul> 5821cb0ef41Sopenharmony_ci</li> 5831cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 5841cb0ef41Sopenharmony_ci<ul> 5851cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 5861cb0ef41Sopenharmony_ci<li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> A string representation of an IPv4 or IPv6 address.</li> 5871cb0ef41Sopenharmony_ci<li><code>family</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> <code>4</code> or <code>6</code>, denoting the family of <code>address</code>, or <code>0</code> if 5881cb0ef41Sopenharmony_cithe address is not an IPv4 or IPv6 address. <code>0</code> is a likely indicator of a 5891cb0ef41Sopenharmony_cibug in the name resolution service used by the operating system.</li> 5901cb0ef41Sopenharmony_ci</ul> 5911cb0ef41Sopenharmony_ci</li> 5921cb0ef41Sopenharmony_ci</ul> 5931cb0ef41Sopenharmony_ci<p>Resolves a host name (e.g. <code>'nodejs.org'</code>) into the first found A (IPv4) or 5941cb0ef41Sopenharmony_ciAAAA (IPv6) record. All <code>option</code> properties are optional. If <code>options</code> is an 5951cb0ef41Sopenharmony_ciinteger, then it must be <code>4</code> or <code>6</code> – if <code>options</code> is <code>0</code> or not provided, then 5961cb0ef41Sopenharmony_ciIPv4 and IPv6 addresses are both returned if found.</p> 5971cb0ef41Sopenharmony_ci<p>With the <code>all</code> option set to <code>true</code>, the arguments for <code>callback</code> change to 5981cb0ef41Sopenharmony_ci<code>(err, addresses)</code>, with <code>addresses</code> being an array of objects with the 5991cb0ef41Sopenharmony_ciproperties <code>address</code> and <code>family</code>.</p> 6001cb0ef41Sopenharmony_ci<p>On error, <code>err</code> is an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> is the error code. 6011cb0ef41Sopenharmony_ciKeep in mind that <code>err.code</code> will be set to <code>'ENOTFOUND'</code> not only when 6021cb0ef41Sopenharmony_cithe host name does not exist but also when the lookup fails in other ways 6031cb0ef41Sopenharmony_cisuch as no available file descriptors.</p> 6041cb0ef41Sopenharmony_ci<p><code>dns.lookup()</code> does not necessarily have anything to do with the DNS protocol. 6051cb0ef41Sopenharmony_ciThe implementation uses an operating system facility that can associate names 6061cb0ef41Sopenharmony_ciwith addresses and vice versa. This implementation can have subtle but 6071cb0ef41Sopenharmony_ciimportant consequences on the behavior of any Node.js program. Please take some 6081cb0ef41Sopenharmony_citime to consult the <a href="#implementation-considerations">Implementation considerations section</a> before using 6091cb0ef41Sopenharmony_ci<code>dns.lookup()</code>.</p> 6101cb0ef41Sopenharmony_ci<p>Example usage:</p> 6111cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> dns = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>); 6121cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> options = { 6131cb0ef41Sopenharmony_ci <span class="hljs-attr">family</span>: <span class="hljs-number">6</span>, 6141cb0ef41Sopenharmony_ci <span class="hljs-attr">hints</span>: dns.<span class="hljs-property">ADDRCONFIG</span> | dns.<span class="hljs-property">V4MAPPED</span>, 6151cb0ef41Sopenharmony_ci}; 6161cb0ef41Sopenharmony_cidns.<span class="hljs-title function_">lookup</span>(<span class="hljs-string">'example.com'</span>, options, <span class="hljs-function">(<span class="hljs-params">err, address, family</span>) =></span> 6171cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'address: %j family: IPv%s'</span>, address, family)); 6181cb0ef41Sopenharmony_ci<span class="hljs-comment">// address: "2606:2800:220:1:248:1893:25c8:1946" family: IPv6</span> 6191cb0ef41Sopenharmony_ci 6201cb0ef41Sopenharmony_ci<span class="hljs-comment">// When options.all is true, the result will be an Array.</span> 6211cb0ef41Sopenharmony_cioptions.<span class="hljs-property">all</span> = <span class="hljs-literal">true</span>; 6221cb0ef41Sopenharmony_cidns.<span class="hljs-title function_">lookup</span>(<span class="hljs-string">'example.com'</span>, options, <span class="hljs-function">(<span class="hljs-params">err, addresses</span>) =></span> 6231cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'addresses: %j'</span>, addresses)); 6241cb0ef41Sopenharmony_ci<span class="hljs-comment">// addresses: [{"address":"2606:2800:220:1:248:1893:25c8:1946","family":6}]</span></code> <button class="copy-button">copy</button></pre> 6251cb0ef41Sopenharmony_ci<p>If this method is invoked as its <a href="util.html#utilpromisifyoriginal"><code>util.promisify()</code></a>ed version, and <code>all</code> 6261cb0ef41Sopenharmony_ciis not set to <code>true</code>, it returns a <code>Promise</code> for an <code>Object</code> with <code>address</code> and 6271cb0ef41Sopenharmony_ci<code>family</code> properties.</p> 6281cb0ef41Sopenharmony_ci<h4>Supported getaddrinfo flags<span><a class="mark" href="#supported-getaddrinfo-flags" id="supported-getaddrinfo-flags">#</a></span><a aria-hidden="true" class="legacy" id="dns_supported_getaddrinfo_flags"></a></h4> 6291cb0ef41Sopenharmony_ci<div class="api_metadata"> 6301cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 6311cb0ef41Sopenharmony_ci<table> 6321cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 6331cb0ef41Sopenharmony_ci<tr><td>v13.13.0, v12.17.0</td> 6341cb0ef41Sopenharmony_ci<td><p>Added support for the <code>dns.ALL</code> flag.</p></td></tr> 6351cb0ef41Sopenharmony_ci</tbody></table> 6361cb0ef41Sopenharmony_ci</details> 6371cb0ef41Sopenharmony_ci</div> 6381cb0ef41Sopenharmony_ci<p>The following flags can be passed as hints to <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a>.</p> 6391cb0ef41Sopenharmony_ci<ul> 6401cb0ef41Sopenharmony_ci<li><code>dns.ADDRCONFIG</code>: Limits returned address types to the types of non-loopback 6411cb0ef41Sopenharmony_ciaddresses configured on the system. For example, IPv4 addresses are only 6421cb0ef41Sopenharmony_cireturned if the current system has at least one IPv4 address configured.</li> 6431cb0ef41Sopenharmony_ci<li><code>dns.V4MAPPED</code>: If the IPv6 family was specified, but no IPv6 addresses were 6441cb0ef41Sopenharmony_cifound, then return IPv4 mapped IPv6 addresses. It is not supported 6451cb0ef41Sopenharmony_cion some operating systems (e.g. FreeBSD 10.1).</li> 6461cb0ef41Sopenharmony_ci<li><code>dns.ALL</code>: If <code>dns.V4MAPPED</code> is specified, return resolved IPv6 addresses as 6471cb0ef41Sopenharmony_ciwell as IPv4 mapped IPv6 addresses.</li> 6481cb0ef41Sopenharmony_ci</ul> 6491cb0ef41Sopenharmony_ci</section><section><h3><code>dns.lookupService(address, port, callback)</code><span><a class="mark" href="#dnslookupserviceaddress-port-callback" id="dnslookupserviceaddress-port-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_lookupservice_address_port_callback"></a></h3> 6501cb0ef41Sopenharmony_ci<div class="api_metadata"> 6511cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 6521cb0ef41Sopenharmony_ci<table> 6531cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 6541cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 6551cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 6561cb0ef41Sopenharmony_ci<tr><td>v0.11.14</td> 6571cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.11.14</span></p></td></tr> 6581cb0ef41Sopenharmony_ci</tbody></table> 6591cb0ef41Sopenharmony_ci</details> 6601cb0ef41Sopenharmony_ci</div> 6611cb0ef41Sopenharmony_ci<ul> 6621cb0ef41Sopenharmony_ci<li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 6631cb0ef41Sopenharmony_ci<li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a></li> 6641cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 6651cb0ef41Sopenharmony_ci<ul> 6661cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 6671cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> e.g. <code>example.com</code></li> 6681cb0ef41Sopenharmony_ci<li><code>service</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> e.g. <code>http</code></li> 6691cb0ef41Sopenharmony_ci</ul> 6701cb0ef41Sopenharmony_ci</li> 6711cb0ef41Sopenharmony_ci</ul> 6721cb0ef41Sopenharmony_ci<p>Resolves the given <code>address</code> and <code>port</code> into a host name and service using 6731cb0ef41Sopenharmony_cithe operating system's underlying <code>getnameinfo</code> implementation.</p> 6741cb0ef41Sopenharmony_ci<p>If <code>address</code> is not a valid IP address, a <code>TypeError</code> will be thrown. 6751cb0ef41Sopenharmony_ciThe <code>port</code> will be coerced to a number. If it is not a legal port, a <code>TypeError</code> 6761cb0ef41Sopenharmony_ciwill be thrown.</p> 6771cb0ef41Sopenharmony_ci<p>On an error, <code>err</code> is an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> is the error code.</p> 6781cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> dns = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>); 6791cb0ef41Sopenharmony_cidns.<span class="hljs-title function_">lookupService</span>(<span class="hljs-string">'127.0.0.1'</span>, <span class="hljs-number">22</span>, <span class="hljs-function">(<span class="hljs-params">err, hostname, service</span>) =></span> { 6801cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(hostname, service); 6811cb0ef41Sopenharmony_ci <span class="hljs-comment">// Prints: localhost ssh</span> 6821cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre> 6831cb0ef41Sopenharmony_ci<p>If this method is invoked as its <a href="util.html#utilpromisifyoriginal"><code>util.promisify()</code></a>ed version, it returns a 6841cb0ef41Sopenharmony_ci<code>Promise</code> for an <code>Object</code> with <code>hostname</code> and <code>service</code> properties.</p> 6851cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolve(hostname[, rrtype], callback)</code><span><a class="mark" href="#dnsresolvehostname-rrtype-callback" id="dnsresolvehostname-rrtype-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolve_hostname_rrtype_callback"></a></h3> 6861cb0ef41Sopenharmony_ci<div class="api_metadata"> 6871cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 6881cb0ef41Sopenharmony_ci<table> 6891cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 6901cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 6911cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 6921cb0ef41Sopenharmony_ci<tr><td>v0.1.27</td> 6931cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.27</span></p></td></tr> 6941cb0ef41Sopenharmony_ci</tbody></table> 6951cb0ef41Sopenharmony_ci</details> 6961cb0ef41Sopenharmony_ci</div> 6971cb0ef41Sopenharmony_ci<ul> 6981cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host name to resolve.</li> 6991cb0ef41Sopenharmony_ci<li><code>rrtype</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Resource record type. <strong>Default:</strong> <code>'A'</code>.</li> 7001cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 7011cb0ef41Sopenharmony_ci<ul> 7021cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 7031cb0ef41Sopenharmony_ci<li><code>records</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></li> 7041cb0ef41Sopenharmony_ci</ul> 7051cb0ef41Sopenharmony_ci</li> 7061cb0ef41Sopenharmony_ci</ul> 7071cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve a host name (e.g. <code>'nodejs.org'</code>) into an array 7081cb0ef41Sopenharmony_ciof the resource records. The <code>callback</code> function has arguments 7091cb0ef41Sopenharmony_ci<code>(err, records)</code>. When successful, <code>records</code> will be an array of resource 7101cb0ef41Sopenharmony_cirecords. The type and structure of individual results varies based on <code>rrtype</code>:</p> 7111cb0ef41Sopenharmony_ci 7121cb0ef41Sopenharmony_ci 7131cb0ef41Sopenharmony_ci 7141cb0ef41Sopenharmony_ci 7151cb0ef41Sopenharmony_ci 7161cb0ef41Sopenharmony_ci 7171cb0ef41Sopenharmony_ci 7181cb0ef41Sopenharmony_ci 7191cb0ef41Sopenharmony_ci 7201cb0ef41Sopenharmony_ci 7211cb0ef41Sopenharmony_ci 7221cb0ef41Sopenharmony_ci 7231cb0ef41Sopenharmony_ci 7241cb0ef41Sopenharmony_ci 7251cb0ef41Sopenharmony_ci 7261cb0ef41Sopenharmony_ci 7271cb0ef41Sopenharmony_ci 7281cb0ef41Sopenharmony_ci 7291cb0ef41Sopenharmony_ci 7301cb0ef41Sopenharmony_ci 7311cb0ef41Sopenharmony_ci 7321cb0ef41Sopenharmony_ci 7331cb0ef41Sopenharmony_ci 7341cb0ef41Sopenharmony_ci 7351cb0ef41Sopenharmony_ci 7361cb0ef41Sopenharmony_ci 7371cb0ef41Sopenharmony_ci 7381cb0ef41Sopenharmony_ci 7391cb0ef41Sopenharmony_ci 7401cb0ef41Sopenharmony_ci 7411cb0ef41Sopenharmony_ci 7421cb0ef41Sopenharmony_ci 7431cb0ef41Sopenharmony_ci 7441cb0ef41Sopenharmony_ci 7451cb0ef41Sopenharmony_ci 7461cb0ef41Sopenharmony_ci 7471cb0ef41Sopenharmony_ci 7481cb0ef41Sopenharmony_ci 7491cb0ef41Sopenharmony_ci 7501cb0ef41Sopenharmony_ci 7511cb0ef41Sopenharmony_ci 7521cb0ef41Sopenharmony_ci 7531cb0ef41Sopenharmony_ci 7541cb0ef41Sopenharmony_ci 7551cb0ef41Sopenharmony_ci 7561cb0ef41Sopenharmony_ci 7571cb0ef41Sopenharmony_ci 7581cb0ef41Sopenharmony_ci 7591cb0ef41Sopenharmony_ci 7601cb0ef41Sopenharmony_ci 7611cb0ef41Sopenharmony_ci 7621cb0ef41Sopenharmony_ci 7631cb0ef41Sopenharmony_ci 7641cb0ef41Sopenharmony_ci 7651cb0ef41Sopenharmony_ci 7661cb0ef41Sopenharmony_ci 7671cb0ef41Sopenharmony_ci 7681cb0ef41Sopenharmony_ci 7691cb0ef41Sopenharmony_ci 7701cb0ef41Sopenharmony_ci 7711cb0ef41Sopenharmony_ci 7721cb0ef41Sopenharmony_ci 7731cb0ef41Sopenharmony_ci 7741cb0ef41Sopenharmony_ci 7751cb0ef41Sopenharmony_ci 7761cb0ef41Sopenharmony_ci 7771cb0ef41Sopenharmony_ci 7781cb0ef41Sopenharmony_ci 7791cb0ef41Sopenharmony_ci 7801cb0ef41Sopenharmony_ci 7811cb0ef41Sopenharmony_ci 7821cb0ef41Sopenharmony_ci 7831cb0ef41Sopenharmony_ci 7841cb0ef41Sopenharmony_ci 7851cb0ef41Sopenharmony_ci 7861cb0ef41Sopenharmony_ci 7871cb0ef41Sopenharmony_ci 7881cb0ef41Sopenharmony_ci 7891cb0ef41Sopenharmony_ci 7901cb0ef41Sopenharmony_ci 7911cb0ef41Sopenharmony_ci 7921cb0ef41Sopenharmony_ci 7931cb0ef41Sopenharmony_ci 7941cb0ef41Sopenharmony_ci<table><thead><tr><th><code>rrtype</code></th><th><code>records</code> contains</th><th>Result type</th><th>Shorthand method</th></tr></thead><tbody><tr><td><code>'A'</code></td><td>IPv4 addresses (default)</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnsresolve4hostname-options-callback"><code>dns.resolve4()</code></a></td></tr><tr><td><code>'AAAA'</code></td><td>IPv6 addresses</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnsresolve6hostname-options-callback"><code>dns.resolve6()</code></a></td></tr><tr><td><code>'ANY'</code></td><td>any records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnsresolveanyhostname-callback"><code>dns.resolveAny()</code></a></td></tr><tr><td><code>'CAA'</code></td><td>CA authorization records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnsresolvecaahostname-callback"><code>dns.resolveCaa()</code></a></td></tr><tr><td><code>'CNAME'</code></td><td>canonical name records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnsresolvecnamehostname-callback"><code>dns.resolveCname()</code></a></td></tr><tr><td><code>'MX'</code></td><td>mail exchange records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnsresolvemxhostname-callback"><code>dns.resolveMx()</code></a></td></tr><tr><td><code>'NAPTR'</code></td><td>name authority pointer records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnsresolvenaptrhostname-callback"><code>dns.resolveNaptr()</code></a></td></tr><tr><td><code>'NS'</code></td><td>name server records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnsresolvenshostname-callback"><code>dns.resolveNs()</code></a></td></tr><tr><td><code>'PTR'</code></td><td>pointer records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnsresolveptrhostname-callback"><code>dns.resolvePtr()</code></a></td></tr><tr><td><code>'SOA'</code></td><td>start of authority records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnsresolvesoahostname-callback"><code>dns.resolveSoa()</code></a></td></tr><tr><td><code>'SRV'</code></td><td>service records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnsresolvesrvhostname-callback"><code>dns.resolveSrv()</code></a></td></tr><tr><td><code>'TXT'</code></td><td>text records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></td><td><a href="#dnsresolvetxthostname-callback"><code>dns.resolveTxt()</code></a></td></tr></tbody></table> 7951cb0ef41Sopenharmony_ci<p>On error, <code>err</code> is an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> is one of the 7961cb0ef41Sopenharmony_ci<a href="#error-codes">DNS error codes</a>.</p> 7971cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolve4(hostname[, options], callback)</code><span><a class="mark" href="#dnsresolve4hostname-options-callback" id="dnsresolve4hostname-options-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolve4_hostname_options_callback"></a></h3> 7981cb0ef41Sopenharmony_ci<div class="api_metadata"> 7991cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 8001cb0ef41Sopenharmony_ci<table> 8011cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 8021cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 8031cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 8041cb0ef41Sopenharmony_ci<tr><td>v7.2.0</td> 8051cb0ef41Sopenharmony_ci<td><p>This method now supports passing <code>options</code>, specifically <code>options.ttl</code>.</p></td></tr> 8061cb0ef41Sopenharmony_ci<tr><td>v0.1.16</td> 8071cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.16</span></p></td></tr> 8081cb0ef41Sopenharmony_ci</tbody></table> 8091cb0ef41Sopenharmony_ci</details> 8101cb0ef41Sopenharmony_ci</div> 8111cb0ef41Sopenharmony_ci<ul> 8121cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host name to resolve.</li> 8131cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 8141cb0ef41Sopenharmony_ci<ul> 8151cb0ef41Sopenharmony_ci<li><code>ttl</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> Retrieves the Time-To-Live value (TTL) of each record. 8161cb0ef41Sopenharmony_ciWhen <code>true</code>, the callback receives an array of 8171cb0ef41Sopenharmony_ci<code>{ address: '1.2.3.4', ttl: 60 }</code> objects rather than an array of strings, 8181cb0ef41Sopenharmony_ciwith the TTL expressed in seconds.</li> 8191cb0ef41Sopenharmony_ci</ul> 8201cb0ef41Sopenharmony_ci</li> 8211cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 8221cb0ef41Sopenharmony_ci<ul> 8231cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 8241cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 8251cb0ef41Sopenharmony_ci</ul> 8261cb0ef41Sopenharmony_ci</li> 8271cb0ef41Sopenharmony_ci</ul> 8281cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve a IPv4 addresses (<code>A</code> records) for the 8291cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> function 8301cb0ef41Sopenharmony_ciwill contain an array of IPv4 addresses (e.g. 8311cb0ef41Sopenharmony_ci<code>['74.125.79.104', '74.125.79.105', '74.125.79.106']</code>).</p> 8321cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolve6(hostname[, options], callback)</code><span><a class="mark" href="#dnsresolve6hostname-options-callback" id="dnsresolve6hostname-options-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolve6_hostname_options_callback"></a></h3> 8331cb0ef41Sopenharmony_ci<div class="api_metadata"> 8341cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 8351cb0ef41Sopenharmony_ci<table> 8361cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 8371cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 8381cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 8391cb0ef41Sopenharmony_ci<tr><td>v7.2.0</td> 8401cb0ef41Sopenharmony_ci<td><p>This method now supports passing <code>options</code>, specifically <code>options.ttl</code>.</p></td></tr> 8411cb0ef41Sopenharmony_ci<tr><td>v0.1.16</td> 8421cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.16</span></p></td></tr> 8431cb0ef41Sopenharmony_ci</tbody></table> 8441cb0ef41Sopenharmony_ci</details> 8451cb0ef41Sopenharmony_ci</div> 8461cb0ef41Sopenharmony_ci<ul> 8471cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host name to resolve.</li> 8481cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 8491cb0ef41Sopenharmony_ci<ul> 8501cb0ef41Sopenharmony_ci<li><code>ttl</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> Retrieve the Time-To-Live value (TTL) of each record. 8511cb0ef41Sopenharmony_ciWhen <code>true</code>, the callback receives an array of 8521cb0ef41Sopenharmony_ci<code>{ address: '0:1:2:3:4:5:6:7', ttl: 60 }</code> objects rather than an array of 8531cb0ef41Sopenharmony_cistrings, with the TTL expressed in seconds.</li> 8541cb0ef41Sopenharmony_ci</ul> 8551cb0ef41Sopenharmony_ci</li> 8561cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 8571cb0ef41Sopenharmony_ci<ul> 8581cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 8591cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 8601cb0ef41Sopenharmony_ci</ul> 8611cb0ef41Sopenharmony_ci</li> 8621cb0ef41Sopenharmony_ci</ul> 8631cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve IPv6 addresses (<code>AAAA</code> records) for the 8641cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> function 8651cb0ef41Sopenharmony_ciwill contain an array of IPv6 addresses.</p> 8661cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveAny(hostname, callback)</code><span><a class="mark" href="#dnsresolveanyhostname-callback" id="dnsresolveanyhostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolveany_hostname_callback"></a></h3> 8671cb0ef41Sopenharmony_ci<div class="api_metadata"> 8681cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 8691cb0ef41Sopenharmony_ci<table> 8701cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 8711cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 8721cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 8731cb0ef41Sopenharmony_ci</tbody></table> 8741cb0ef41Sopenharmony_ci</details> 8751cb0ef41Sopenharmony_ci</div> 8761cb0ef41Sopenharmony_ci<ul> 8771cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 8781cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 8791cb0ef41Sopenharmony_ci<ul> 8801cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 8811cb0ef41Sopenharmony_ci<li><code>ret</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 8821cb0ef41Sopenharmony_ci</ul> 8831cb0ef41Sopenharmony_ci</li> 8841cb0ef41Sopenharmony_ci</ul> 8851cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve all records (also known as <code>ANY</code> or <code>*</code> query). 8861cb0ef41Sopenharmony_ciThe <code>ret</code> argument passed to the <code>callback</code> function will be an array containing 8871cb0ef41Sopenharmony_civarious types of records. Each object has a property <code>type</code> that indicates the 8881cb0ef41Sopenharmony_citype of the current record. And depending on the <code>type</code>, additional properties 8891cb0ef41Sopenharmony_ciwill be present on the object:</p> 8901cb0ef41Sopenharmony_ci 8911cb0ef41Sopenharmony_ci 8921cb0ef41Sopenharmony_ci 8931cb0ef41Sopenharmony_ci 8941cb0ef41Sopenharmony_ci 8951cb0ef41Sopenharmony_ci 8961cb0ef41Sopenharmony_ci 8971cb0ef41Sopenharmony_ci 8981cb0ef41Sopenharmony_ci 8991cb0ef41Sopenharmony_ci 9001cb0ef41Sopenharmony_ci 9011cb0ef41Sopenharmony_ci 9021cb0ef41Sopenharmony_ci 9031cb0ef41Sopenharmony_ci 9041cb0ef41Sopenharmony_ci 9051cb0ef41Sopenharmony_ci 9061cb0ef41Sopenharmony_ci 9071cb0ef41Sopenharmony_ci 9081cb0ef41Sopenharmony_ci 9091cb0ef41Sopenharmony_ci 9101cb0ef41Sopenharmony_ci 9111cb0ef41Sopenharmony_ci 9121cb0ef41Sopenharmony_ci 9131cb0ef41Sopenharmony_ci 9141cb0ef41Sopenharmony_ci 9151cb0ef41Sopenharmony_ci 9161cb0ef41Sopenharmony_ci 9171cb0ef41Sopenharmony_ci 9181cb0ef41Sopenharmony_ci 9191cb0ef41Sopenharmony_ci 9201cb0ef41Sopenharmony_ci 9211cb0ef41Sopenharmony_ci 9221cb0ef41Sopenharmony_ci 9231cb0ef41Sopenharmony_ci 9241cb0ef41Sopenharmony_ci 9251cb0ef41Sopenharmony_ci 9261cb0ef41Sopenharmony_ci 9271cb0ef41Sopenharmony_ci 9281cb0ef41Sopenharmony_ci 9291cb0ef41Sopenharmony_ci 9301cb0ef41Sopenharmony_ci 9311cb0ef41Sopenharmony_ci 9321cb0ef41Sopenharmony_ci 9331cb0ef41Sopenharmony_ci 9341cb0ef41Sopenharmony_ci 9351cb0ef41Sopenharmony_ci 9361cb0ef41Sopenharmony_ci 9371cb0ef41Sopenharmony_ci 9381cb0ef41Sopenharmony_ci 9391cb0ef41Sopenharmony_ci<table><thead><tr><th>Type</th><th>Properties</th></tr></thead><tbody><tr><td><code>'A'</code></td><td><code>address</code>/<code>ttl</code></td></tr><tr><td><code>'AAAA'</code></td><td><code>address</code>/<code>ttl</code></td></tr><tr><td><code>'CNAME'</code></td><td><code>value</code></td></tr><tr><td><code>'MX'</code></td><td>Refer to <a href="#dnsresolvemxhostname-callback"><code>dns.resolveMx()</code></a></td></tr><tr><td><code>'NAPTR'</code></td><td>Refer to <a href="#dnsresolvenaptrhostname-callback"><code>dns.resolveNaptr()</code></a></td></tr><tr><td><code>'NS'</code></td><td><code>value</code></td></tr><tr><td><code>'PTR'</code></td><td><code>value</code></td></tr><tr><td><code>'SOA'</code></td><td>Refer to <a href="#dnsresolvesoahostname-callback"><code>dns.resolveSoa()</code></a></td></tr><tr><td><code>'SRV'</code></td><td>Refer to <a href="#dnsresolvesrvhostname-callback"><code>dns.resolveSrv()</code></a></td></tr><tr><td><code>'TXT'</code></td><td>This type of record contains an array property called <code>entries</code> which refers to <a href="#dnsresolvetxthostname-callback"><code>dns.resolveTxt()</code></a>, e.g. <code>{ entries: ['...'], type: 'TXT' }</code></td></tr></tbody></table> 9401cb0ef41Sopenharmony_ci<p>Here is an example of the <code>ret</code> object passed to the callback:</p> 9411cb0ef41Sopenharmony_ci<!-- eslint-disable semi --> 9421cb0ef41Sopenharmony_ci<pre><code class="language-js">[ { <span class="hljs-attr">type</span>: <span class="hljs-string">'A'</span>, <span class="hljs-attr">address</span>: <span class="hljs-string">'127.0.0.1'</span>, <span class="hljs-attr">ttl</span>: <span class="hljs-number">299</span> }, 9431cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'CNAME'</span>, <span class="hljs-attr">value</span>: <span class="hljs-string">'example.com'</span> }, 9441cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'MX'</span>, <span class="hljs-attr">exchange</span>: <span class="hljs-string">'alt4.aspmx.l.example.com'</span>, <span class="hljs-attr">priority</span>: <span class="hljs-number">50</span> }, 9451cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'NS'</span>, <span class="hljs-attr">value</span>: <span class="hljs-string">'ns1.example.com'</span> }, 9461cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'TXT'</span>, <span class="hljs-attr">entries</span>: [ <span class="hljs-string">'v=spf1 include:_spf.example.com ~all'</span> ] }, 9471cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'SOA'</span>, 9481cb0ef41Sopenharmony_ci <span class="hljs-attr">nsname</span>: <span class="hljs-string">'ns1.example.com'</span>, 9491cb0ef41Sopenharmony_ci <span class="hljs-attr">hostmaster</span>: <span class="hljs-string">'admin.example.com'</span>, 9501cb0ef41Sopenharmony_ci <span class="hljs-attr">serial</span>: <span class="hljs-number">156696742</span>, 9511cb0ef41Sopenharmony_ci <span class="hljs-attr">refresh</span>: <span class="hljs-number">900</span>, 9521cb0ef41Sopenharmony_ci <span class="hljs-attr">retry</span>: <span class="hljs-number">900</span>, 9531cb0ef41Sopenharmony_ci <span class="hljs-attr">expire</span>: <span class="hljs-number">1800</span>, 9541cb0ef41Sopenharmony_ci <span class="hljs-attr">minttl</span>: <span class="hljs-number">60</span> } ]</code> <button class="copy-button">copy</button></pre> 9551cb0ef41Sopenharmony_ci<p>DNS server operators may choose not to respond to <code>ANY</code> 9561cb0ef41Sopenharmony_ciqueries. It may be better to call individual methods like <a href="#dnsresolve4hostname-options-callback"><code>dns.resolve4()</code></a>, 9571cb0ef41Sopenharmony_ci<a href="#dnsresolvemxhostname-callback"><code>dns.resolveMx()</code></a>, and so on. For more details, see <a href="https://tools.ietf.org/html/rfc8482">RFC 8482</a>.</p> 9581cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveCname(hostname, callback)</code><span><a class="mark" href="#dnsresolvecnamehostname-callback" id="dnsresolvecnamehostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvecname_hostname_callback"></a></h3> 9591cb0ef41Sopenharmony_ci<div class="api_metadata"> 9601cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 9611cb0ef41Sopenharmony_ci<table> 9621cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 9631cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 9641cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 9651cb0ef41Sopenharmony_ci<tr><td>v0.3.2</td> 9661cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.3.2</span></p></td></tr> 9671cb0ef41Sopenharmony_ci</tbody></table> 9681cb0ef41Sopenharmony_ci</details> 9691cb0ef41Sopenharmony_ci</div> 9701cb0ef41Sopenharmony_ci<ul> 9711cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 9721cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 9731cb0ef41Sopenharmony_ci<ul> 9741cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 9751cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></li> 9761cb0ef41Sopenharmony_ci</ul> 9771cb0ef41Sopenharmony_ci</li> 9781cb0ef41Sopenharmony_ci</ul> 9791cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve <code>CNAME</code> records for the <code>hostname</code>. The 9801cb0ef41Sopenharmony_ci<code>addresses</code> argument passed to the <code>callback</code> function 9811cb0ef41Sopenharmony_ciwill contain an array of canonical name records available for the <code>hostname</code> 9821cb0ef41Sopenharmony_ci(e.g. <code>['bar.example.com']</code>).</p> 9831cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveCaa(hostname, callback)</code><span><a class="mark" href="#dnsresolvecaahostname-callback" id="dnsresolvecaahostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvecaa_hostname_callback"></a></h3> 9841cb0ef41Sopenharmony_ci<div class="api_metadata"> 9851cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 9861cb0ef41Sopenharmony_ci<table> 9871cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 9881cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 9891cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 9901cb0ef41Sopenharmony_ci<tr><td>v15.0.0, v14.17.0</td> 9911cb0ef41Sopenharmony_ci<td><p><span>Added in: v15.0.0, v14.17.0</span></p></td></tr> 9921cb0ef41Sopenharmony_ci</tbody></table> 9931cb0ef41Sopenharmony_ci</details> 9941cb0ef41Sopenharmony_ci</div> 9951cb0ef41Sopenharmony_ci<ul> 9961cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 9971cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 9981cb0ef41Sopenharmony_ci<ul> 9991cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 10001cb0ef41Sopenharmony_ci<li><code>records</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 10011cb0ef41Sopenharmony_ci</ul> 10021cb0ef41Sopenharmony_ci</li> 10031cb0ef41Sopenharmony_ci</ul> 10041cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve <code>CAA</code> records for the <code>hostname</code>. The 10051cb0ef41Sopenharmony_ci<code>addresses</code> argument passed to the <code>callback</code> function 10061cb0ef41Sopenharmony_ciwill contain an array of certification authority authorization records 10071cb0ef41Sopenharmony_ciavailable for the <code>hostname</code> (e.g. <code>[{critical: 0, iodef: 'mailto:pki@example.com'}, {critical: 128, issue: 'pki.example.com'}]</code>).</p> 10081cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveMx(hostname, callback)</code><span><a class="mark" href="#dnsresolvemxhostname-callback" id="dnsresolvemxhostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvemx_hostname_callback"></a></h3> 10091cb0ef41Sopenharmony_ci<div class="api_metadata"> 10101cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 10111cb0ef41Sopenharmony_ci<table> 10121cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 10131cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 10141cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 10151cb0ef41Sopenharmony_ci<tr><td>v0.1.27</td> 10161cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.27</span></p></td></tr> 10171cb0ef41Sopenharmony_ci</tbody></table> 10181cb0ef41Sopenharmony_ci</details> 10191cb0ef41Sopenharmony_ci</div> 10201cb0ef41Sopenharmony_ci<ul> 10211cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 10221cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 10231cb0ef41Sopenharmony_ci<ul> 10241cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 10251cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 10261cb0ef41Sopenharmony_ci</ul> 10271cb0ef41Sopenharmony_ci</li> 10281cb0ef41Sopenharmony_ci</ul> 10291cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve mail exchange records (<code>MX</code> records) for the 10301cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> function will 10311cb0ef41Sopenharmony_cicontain an array of objects containing both a <code>priority</code> and <code>exchange</code> 10321cb0ef41Sopenharmony_ciproperty (e.g. <code>[{priority: 10, exchange: 'mx.example.com'}, ...]</code>).</p> 10331cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveNaptr(hostname, callback)</code><span><a class="mark" href="#dnsresolvenaptrhostname-callback" id="dnsresolvenaptrhostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvenaptr_hostname_callback"></a></h3> 10341cb0ef41Sopenharmony_ci<div class="api_metadata"> 10351cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 10361cb0ef41Sopenharmony_ci<table> 10371cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 10381cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 10391cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 10401cb0ef41Sopenharmony_ci<tr><td>v0.9.12</td> 10411cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.9.12</span></p></td></tr> 10421cb0ef41Sopenharmony_ci</tbody></table> 10431cb0ef41Sopenharmony_ci</details> 10441cb0ef41Sopenharmony_ci</div> 10451cb0ef41Sopenharmony_ci<ul> 10461cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 10471cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 10481cb0ef41Sopenharmony_ci<ul> 10491cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 10501cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 10511cb0ef41Sopenharmony_ci</ul> 10521cb0ef41Sopenharmony_ci</li> 10531cb0ef41Sopenharmony_ci</ul> 10541cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve regular expression-based records (<code>NAPTR</code> 10551cb0ef41Sopenharmony_cirecords) for the <code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> 10561cb0ef41Sopenharmony_cifunction will contain an array of objects with the following properties:</p> 10571cb0ef41Sopenharmony_ci<ul> 10581cb0ef41Sopenharmony_ci<li><code>flags</code></li> 10591cb0ef41Sopenharmony_ci<li><code>service</code></li> 10601cb0ef41Sopenharmony_ci<li><code>regexp</code></li> 10611cb0ef41Sopenharmony_ci<li><code>replacement</code></li> 10621cb0ef41Sopenharmony_ci<li><code>order</code></li> 10631cb0ef41Sopenharmony_ci<li><code>preference</code></li> 10641cb0ef41Sopenharmony_ci</ul> 10651cb0ef41Sopenharmony_ci<!-- eslint-skip --> 10661cb0ef41Sopenharmony_ci<pre><code class="language-js">{ 10671cb0ef41Sopenharmony_ci <span class="hljs-attr">flags</span>: <span class="hljs-string">'s'</span>, 10681cb0ef41Sopenharmony_ci <span class="hljs-attr">service</span>: <span class="hljs-string">'SIP+D2U'</span>, 10691cb0ef41Sopenharmony_ci <span class="hljs-attr">regexp</span>: <span class="hljs-string">''</span>, 10701cb0ef41Sopenharmony_ci <span class="hljs-attr">replacement</span>: <span class="hljs-string">'_sip._udp.example.com'</span>, 10711cb0ef41Sopenharmony_ci <span class="hljs-attr">order</span>: <span class="hljs-number">30</span>, 10721cb0ef41Sopenharmony_ci <span class="hljs-attr">preference</span>: <span class="hljs-number">100</span> 10731cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre> 10741cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveNs(hostname, callback)</code><span><a class="mark" href="#dnsresolvenshostname-callback" id="dnsresolvenshostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvens_hostname_callback"></a></h3> 10751cb0ef41Sopenharmony_ci<div class="api_metadata"> 10761cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 10771cb0ef41Sopenharmony_ci<table> 10781cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 10791cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 10801cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 10811cb0ef41Sopenharmony_ci<tr><td>v0.1.90</td> 10821cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.90</span></p></td></tr> 10831cb0ef41Sopenharmony_ci</tbody></table> 10841cb0ef41Sopenharmony_ci</details> 10851cb0ef41Sopenharmony_ci</div> 10861cb0ef41Sopenharmony_ci<ul> 10871cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 10881cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 10891cb0ef41Sopenharmony_ci<ul> 10901cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 10911cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></li> 10921cb0ef41Sopenharmony_ci</ul> 10931cb0ef41Sopenharmony_ci</li> 10941cb0ef41Sopenharmony_ci</ul> 10951cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve name server records (<code>NS</code> records) for the 10961cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> function will 10971cb0ef41Sopenharmony_cicontain an array of name server records available for <code>hostname</code> 10981cb0ef41Sopenharmony_ci(e.g. <code>['ns1.example.com', 'ns2.example.com']</code>).</p> 10991cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolvePtr(hostname, callback)</code><span><a class="mark" href="#dnsresolveptrhostname-callback" id="dnsresolveptrhostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolveptr_hostname_callback"></a></h3> 11001cb0ef41Sopenharmony_ci<div class="api_metadata"> 11011cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 11021cb0ef41Sopenharmony_ci<table> 11031cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 11041cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 11051cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 11061cb0ef41Sopenharmony_ci<tr><td>v6.0.0</td> 11071cb0ef41Sopenharmony_ci<td><p><span>Added in: v6.0.0</span></p></td></tr> 11081cb0ef41Sopenharmony_ci</tbody></table> 11091cb0ef41Sopenharmony_ci</details> 11101cb0ef41Sopenharmony_ci</div> 11111cb0ef41Sopenharmony_ci<ul> 11121cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 11131cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 11141cb0ef41Sopenharmony_ci<ul> 11151cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 11161cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></li> 11171cb0ef41Sopenharmony_ci</ul> 11181cb0ef41Sopenharmony_ci</li> 11191cb0ef41Sopenharmony_ci</ul> 11201cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve pointer records (<code>PTR</code> records) for the 11211cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> function will 11221cb0ef41Sopenharmony_cibe an array of strings containing the reply records.</p> 11231cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveSoa(hostname, callback)</code><span><a class="mark" href="#dnsresolvesoahostname-callback" id="dnsresolvesoahostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvesoa_hostname_callback"></a></h3> 11241cb0ef41Sopenharmony_ci<div class="api_metadata"> 11251cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 11261cb0ef41Sopenharmony_ci<table> 11271cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 11281cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 11291cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 11301cb0ef41Sopenharmony_ci<tr><td>v0.11.10</td> 11311cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.11.10</span></p></td></tr> 11321cb0ef41Sopenharmony_ci</tbody></table> 11331cb0ef41Sopenharmony_ci</details> 11341cb0ef41Sopenharmony_ci</div> 11351cb0ef41Sopenharmony_ci<ul> 11361cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 11371cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 11381cb0ef41Sopenharmony_ci<ul> 11391cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 11401cb0ef41Sopenharmony_ci<li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></li> 11411cb0ef41Sopenharmony_ci</ul> 11421cb0ef41Sopenharmony_ci</li> 11431cb0ef41Sopenharmony_ci</ul> 11441cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve a start of authority record (<code>SOA</code> record) for 11451cb0ef41Sopenharmony_cithe <code>hostname</code>. The <code>address</code> argument passed to the <code>callback</code> function will 11461cb0ef41Sopenharmony_cibe an object with the following properties:</p> 11471cb0ef41Sopenharmony_ci<ul> 11481cb0ef41Sopenharmony_ci<li><code>nsname</code></li> 11491cb0ef41Sopenharmony_ci<li><code>hostmaster</code></li> 11501cb0ef41Sopenharmony_ci<li><code>serial</code></li> 11511cb0ef41Sopenharmony_ci<li><code>refresh</code></li> 11521cb0ef41Sopenharmony_ci<li><code>retry</code></li> 11531cb0ef41Sopenharmony_ci<li><code>expire</code></li> 11541cb0ef41Sopenharmony_ci<li><code>minttl</code></li> 11551cb0ef41Sopenharmony_ci</ul> 11561cb0ef41Sopenharmony_ci<!-- eslint-skip --> 11571cb0ef41Sopenharmony_ci<pre><code class="language-js">{ 11581cb0ef41Sopenharmony_ci <span class="hljs-attr">nsname</span>: <span class="hljs-string">'ns.example.com'</span>, 11591cb0ef41Sopenharmony_ci <span class="hljs-attr">hostmaster</span>: <span class="hljs-string">'root.example.com'</span>, 11601cb0ef41Sopenharmony_ci <span class="hljs-attr">serial</span>: <span class="hljs-number">2013101809</span>, 11611cb0ef41Sopenharmony_ci <span class="hljs-attr">refresh</span>: <span class="hljs-number">10000</span>, 11621cb0ef41Sopenharmony_ci <span class="hljs-attr">retry</span>: <span class="hljs-number">2400</span>, 11631cb0ef41Sopenharmony_ci <span class="hljs-attr">expire</span>: <span class="hljs-number">604800</span>, 11641cb0ef41Sopenharmony_ci <span class="hljs-attr">minttl</span>: <span class="hljs-number">3600</span> 11651cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre> 11661cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveSrv(hostname, callback)</code><span><a class="mark" href="#dnsresolvesrvhostname-callback" id="dnsresolvesrvhostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvesrv_hostname_callback"></a></h3> 11671cb0ef41Sopenharmony_ci<div class="api_metadata"> 11681cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 11691cb0ef41Sopenharmony_ci<table> 11701cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 11711cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 11721cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 11731cb0ef41Sopenharmony_ci<tr><td>v0.1.27</td> 11741cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.27</span></p></td></tr> 11751cb0ef41Sopenharmony_ci</tbody></table> 11761cb0ef41Sopenharmony_ci</details> 11771cb0ef41Sopenharmony_ci</div> 11781cb0ef41Sopenharmony_ci<ul> 11791cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 11801cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 11811cb0ef41Sopenharmony_ci<ul> 11821cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 11831cb0ef41Sopenharmony_ci<li><code>addresses</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object[]></a></li> 11841cb0ef41Sopenharmony_ci</ul> 11851cb0ef41Sopenharmony_ci</li> 11861cb0ef41Sopenharmony_ci</ul> 11871cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve service records (<code>SRV</code> records) for the 11881cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>addresses</code> argument passed to the <code>callback</code> function will 11891cb0ef41Sopenharmony_cibe an array of objects with the following properties:</p> 11901cb0ef41Sopenharmony_ci<ul> 11911cb0ef41Sopenharmony_ci<li><code>priority</code></li> 11921cb0ef41Sopenharmony_ci<li><code>weight</code></li> 11931cb0ef41Sopenharmony_ci<li><code>port</code></li> 11941cb0ef41Sopenharmony_ci<li><code>name</code></li> 11951cb0ef41Sopenharmony_ci</ul> 11961cb0ef41Sopenharmony_ci<!-- eslint-skip --> 11971cb0ef41Sopenharmony_ci<pre><code class="language-js">{ 11981cb0ef41Sopenharmony_ci <span class="hljs-attr">priority</span>: <span class="hljs-number">10</span>, 11991cb0ef41Sopenharmony_ci <span class="hljs-attr">weight</span>: <span class="hljs-number">5</span>, 12001cb0ef41Sopenharmony_ci <span class="hljs-attr">port</span>: <span class="hljs-number">21223</span>, 12011cb0ef41Sopenharmony_ci <span class="hljs-attr">name</span>: <span class="hljs-string">'service.example.com'</span> 12021cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre> 12031cb0ef41Sopenharmony_ci</section><section><h3><code>dns.resolveTxt(hostname, callback)</code><span><a class="mark" href="#dnsresolvetxthostname-callback" id="dnsresolvetxthostname-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolvetxt_hostname_callback"></a></h3> 12041cb0ef41Sopenharmony_ci<div class="api_metadata"> 12051cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 12061cb0ef41Sopenharmony_ci<table> 12071cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 12081cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 12091cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 12101cb0ef41Sopenharmony_ci<tr><td>v0.1.27</td> 12111cb0ef41Sopenharmony_ci<td><p><span>Added in: v0.1.27</span></p></td></tr> 12121cb0ef41Sopenharmony_ci</tbody></table> 12131cb0ef41Sopenharmony_ci</details> 12141cb0ef41Sopenharmony_ci</div> 12151cb0ef41Sopenharmony_ci<!--lint disable no-undefined-references list-item-bullet-indent--> 12161cb0ef41Sopenharmony_ci<ul> 12171cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 12181cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 12191cb0ef41Sopenharmony_ci<ul> 12201cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 12211cb0ef41Sopenharmony_ci<li><code>records</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[][]></a></li> 12221cb0ef41Sopenharmony_ci</ul> 12231cb0ef41Sopenharmony_ci</li> 12241cb0ef41Sopenharmony_ci</ul> 12251cb0ef41Sopenharmony_ci<!--lint enable no-undefined-references list-item-bullet-indent--> 12261cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve text queries (<code>TXT</code> records) for the 12271cb0ef41Sopenharmony_ci<code>hostname</code>. The <code>records</code> argument passed to the <code>callback</code> function is a 12281cb0ef41Sopenharmony_citwo-dimensional array of the text records available for <code>hostname</code> (e.g. 12291cb0ef41Sopenharmony_ci<code>[ ['v=spf1 ip4:0.0.0.0 ', '~all' ] ]</code>). Each sub-array contains TXT chunks of 12301cb0ef41Sopenharmony_cione record. Depending on the use case, these could be either joined together or 12311cb0ef41Sopenharmony_citreated separately.</p> 12321cb0ef41Sopenharmony_ci</section><section><h3><code>dns.reverse(ip, callback)</code><span><a class="mark" href="#dnsreverseip-callback" id="dnsreverseip-callback">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_reverse_ip_callback"></a></h3> 12331cb0ef41Sopenharmony_ci<div class="api_metadata"> 12341cb0ef41Sopenharmony_ci<span>Added in: v0.1.16</span> 12351cb0ef41Sopenharmony_ci</div> 12361cb0ef41Sopenharmony_ci<ul> 12371cb0ef41Sopenharmony_ci<li><code>ip</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 12381cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> 12391cb0ef41Sopenharmony_ci<ul> 12401cb0ef41Sopenharmony_ci<li><code>err</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> 12411cb0ef41Sopenharmony_ci<li><code>hostnames</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></li> 12421cb0ef41Sopenharmony_ci</ul> 12431cb0ef41Sopenharmony_ci</li> 12441cb0ef41Sopenharmony_ci</ul> 12451cb0ef41Sopenharmony_ci<p>Performs a reverse DNS query that resolves an IPv4 or IPv6 address to an 12461cb0ef41Sopenharmony_ciarray of host names.</p> 12471cb0ef41Sopenharmony_ci<p>On error, <code>err</code> is an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> is 12481cb0ef41Sopenharmony_cione of the <a href="#error-codes">DNS error codes</a>.</p> 12491cb0ef41Sopenharmony_ci</section><section><h3><code>dns.setDefaultResultOrder(order)</code><span><a class="mark" href="#dnssetdefaultresultorderorder" id="dnssetdefaultresultorderorder">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_setdefaultresultorder_order"></a></h3> 12501cb0ef41Sopenharmony_ci<div class="api_metadata"> 12511cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 12521cb0ef41Sopenharmony_ci<table> 12531cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 12541cb0ef41Sopenharmony_ci<tr><td>v17.0.0</td> 12551cb0ef41Sopenharmony_ci<td><p>Changed default value to <code>verbatim</code>.</p></td></tr> 12561cb0ef41Sopenharmony_ci<tr><td>v16.4.0, v14.18.0</td> 12571cb0ef41Sopenharmony_ci<td><p><span>Added in: v16.4.0, v14.18.0</span></p></td></tr> 12581cb0ef41Sopenharmony_ci</tbody></table> 12591cb0ef41Sopenharmony_ci</details> 12601cb0ef41Sopenharmony_ci</div> 12611cb0ef41Sopenharmony_ci<ul> 12621cb0ef41Sopenharmony_ci<li><code>order</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> must be <code>'ipv4first'</code> or <code>'verbatim'</code>.</li> 12631cb0ef41Sopenharmony_ci</ul> 12641cb0ef41Sopenharmony_ci<p>Set the default value of <code>verbatim</code> in <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> and 12651cb0ef41Sopenharmony_ci<a href="#dnspromiseslookuphostname-options"><code>dnsPromises.lookup()</code></a>. The value could be:</p> 12661cb0ef41Sopenharmony_ci<ul> 12671cb0ef41Sopenharmony_ci<li><code>ipv4first</code>: sets default <code>verbatim</code> <code>false</code>.</li> 12681cb0ef41Sopenharmony_ci<li><code>verbatim</code>: sets default <code>verbatim</code> <code>true</code>.</li> 12691cb0ef41Sopenharmony_ci</ul> 12701cb0ef41Sopenharmony_ci<p>The default is <code>verbatim</code> and <a href="#dnssetdefaultresultorderorder"><code>dns.setDefaultResultOrder()</code></a> have higher 12711cb0ef41Sopenharmony_cipriority than <a href="cli.html#--dns-result-orderorder"><code>--dns-result-order</code></a>. When using <a href="worker_threads.html">worker threads</a>, 12721cb0ef41Sopenharmony_ci<a href="#dnssetdefaultresultorderorder"><code>dns.setDefaultResultOrder()</code></a> from the main thread won't affect the default 12731cb0ef41Sopenharmony_cidns orders in workers.</p> 12741cb0ef41Sopenharmony_ci</section><section><h3><code>dns.getDefaultResultOrder()</code><span><a class="mark" href="#dnsgetdefaultresultorder" id="dnsgetdefaultresultorder">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_getdefaultresultorder"></a></h3> 12751cb0ef41Sopenharmony_ci<div class="api_metadata"> 12761cb0ef41Sopenharmony_ci<span>Added in: v18.17.0</span> 12771cb0ef41Sopenharmony_ci</div> 12781cb0ef41Sopenharmony_ci<p>Get the default value for <code>verbatim</code> in <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> and 12791cb0ef41Sopenharmony_ci<a href="#dnspromiseslookuphostname-options"><code>dnsPromises.lookup()</code></a>. The value could be:</p> 12801cb0ef41Sopenharmony_ci<ul> 12811cb0ef41Sopenharmony_ci<li><code>ipv4first</code>: for <code>verbatim</code> defaulting to <code>false</code>.</li> 12821cb0ef41Sopenharmony_ci<li><code>verbatim</code>: for <code>verbatim</code> defaulting to <code>true</code>.</li> 12831cb0ef41Sopenharmony_ci</ul> 12841cb0ef41Sopenharmony_ci</section><section><h3><code>dns.setServers(servers)</code><span><a class="mark" href="#dnssetserversservers" id="dnssetserversservers">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_setservers_servers"></a></h3> 12851cb0ef41Sopenharmony_ci<div class="api_metadata"> 12861cb0ef41Sopenharmony_ci<span>Added in: v0.11.3</span> 12871cb0ef41Sopenharmony_ci</div> 12881cb0ef41Sopenharmony_ci<ul> 12891cb0ef41Sopenharmony_ci<li><code>servers</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> array of <a href="https://tools.ietf.org/html/rfc5952#section-6">RFC 5952</a> formatted addresses</li> 12901cb0ef41Sopenharmony_ci</ul> 12911cb0ef41Sopenharmony_ci<p>Sets the IP address and port of servers to be used when performing DNS 12921cb0ef41Sopenharmony_ciresolution. The <code>servers</code> argument is an array of <a href="https://tools.ietf.org/html/rfc5952#section-6">RFC 5952</a> formatted 12931cb0ef41Sopenharmony_ciaddresses. If the port is the IANA default DNS port (53) it can be omitted.</p> 12941cb0ef41Sopenharmony_ci<pre><code class="language-js">dns.<span class="hljs-title function_">setServers</span>([ 12951cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4'</span>, 12961cb0ef41Sopenharmony_ci <span class="hljs-string">'[2001:4860:4860::8888]'</span>, 12971cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4:1053'</span>, 12981cb0ef41Sopenharmony_ci <span class="hljs-string">'[2001:4860:4860::8888]:1053'</span>, 12991cb0ef41Sopenharmony_ci]);</code> <button class="copy-button">copy</button></pre> 13001cb0ef41Sopenharmony_ci<p>An error will be thrown if an invalid address is provided.</p> 13011cb0ef41Sopenharmony_ci<p>The <code>dns.setServers()</code> method must not be called while a DNS query is in 13021cb0ef41Sopenharmony_ciprogress.</p> 13031cb0ef41Sopenharmony_ci<p>The <a href="#dnssetserversservers"><code>dns.setServers()</code></a> method affects only <a href="#dnsresolvehostname-rrtype-callback"><code>dns.resolve()</code></a>, 13041cb0ef41Sopenharmony_ci<code>dns.resolve*()</code> and <a href="#dnsreverseip-callback"><code>dns.reverse()</code></a> (and specifically <em>not</em> 13051cb0ef41Sopenharmony_ci<a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a>).</p> 13061cb0ef41Sopenharmony_ci<p>This method works much like 13071cb0ef41Sopenharmony_ci<a href="https://man7.org/linux/man-pages/man5/resolv.conf.5.html">resolve.conf</a>. 13081cb0ef41Sopenharmony_ciThat is, if attempting to resolve with the first server provided results in a 13091cb0ef41Sopenharmony_ci<code>NOTFOUND</code> error, the <code>resolve()</code> method will <em>not</em> attempt to resolve with 13101cb0ef41Sopenharmony_cisubsequent servers provided. Fallback DNS servers will only be used if the 13111cb0ef41Sopenharmony_ciearlier ones time out or result in some other error.</p> 13121cb0ef41Sopenharmony_ci</section><section><h3>DNS promises API<span><a class="mark" href="#dns-promises-api" id="dns-promises-api">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_promises_api"></a></h3> 13131cb0ef41Sopenharmony_ci<div class="api_metadata"> 13141cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 13151cb0ef41Sopenharmony_ci<table> 13161cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 13171cb0ef41Sopenharmony_ci<tr><td>v15.0.0</td> 13181cb0ef41Sopenharmony_ci<td><p>Exposed as <code>require('dns/promises')</code>.</p></td></tr> 13191cb0ef41Sopenharmony_ci<tr><td>v11.14.0, v10.17.0</td> 13201cb0ef41Sopenharmony_ci<td><p>This API is no longer experimental.</p></td></tr> 13211cb0ef41Sopenharmony_ci<tr><td>v10.6.0</td> 13221cb0ef41Sopenharmony_ci<td><p><span>Added in: v10.6.0</span></p></td></tr> 13231cb0ef41Sopenharmony_ci</tbody></table> 13241cb0ef41Sopenharmony_ci</details> 13251cb0ef41Sopenharmony_ci</div> 13261cb0ef41Sopenharmony_ci<p>The <code>dns.promises</code> API provides an alternative set of asynchronous DNS methods 13271cb0ef41Sopenharmony_cithat return <code>Promise</code> objects rather than using callbacks. The API is accessible 13281cb0ef41Sopenharmony_civia <code>require('node:dns').promises</code> or <code>require('node:dns/promises')</code>.</p> 13291cb0ef41Sopenharmony_ci<h4>Class: <code>dnsPromises.Resolver</code><span><a class="mark" href="#class-dnspromisesresolver" id="class-dnspromisesresolver">#</a></span><a aria-hidden="true" class="legacy" id="dns_class_dnspromises_resolver"></a></h4> 13301cb0ef41Sopenharmony_ci<div class="api_metadata"> 13311cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 13321cb0ef41Sopenharmony_ci</div> 13331cb0ef41Sopenharmony_ci<p>An independent resolver for DNS requests.</p> 13341cb0ef41Sopenharmony_ci<p>Creating a new resolver uses the default server settings. Setting 13351cb0ef41Sopenharmony_cithe servers used for a resolver using 13361cb0ef41Sopenharmony_ci<a href="#dnspromisessetserversservers"><code>resolver.setServers()</code></a> does not affect 13371cb0ef41Sopenharmony_ciother resolvers:</p> 13381cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> { <span class="hljs-title class_">Resolver</span> } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>).<span class="hljs-property">promises</span>; 13391cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> resolver = <span class="hljs-keyword">new</span> <span class="hljs-title class_">Resolver</span>(); 13401cb0ef41Sopenharmony_ciresolver.<span class="hljs-title function_">setServers</span>([<span class="hljs-string">'4.4.4.4'</span>]); 13411cb0ef41Sopenharmony_ci 13421cb0ef41Sopenharmony_ci<span class="hljs-comment">// This request will use the server at 4.4.4.4, independent of global settings.</span> 13431cb0ef41Sopenharmony_ciresolver.<span class="hljs-title function_">resolve4</span>(<span class="hljs-string">'example.org'</span>).<span class="hljs-title function_">then</span>(<span class="hljs-function">(<span class="hljs-params">addresses</span>) =></span> { 13441cb0ef41Sopenharmony_ci <span class="hljs-comment">// ...</span> 13451cb0ef41Sopenharmony_ci}); 13461cb0ef41Sopenharmony_ci 13471cb0ef41Sopenharmony_ci<span class="hljs-comment">// Alternatively, the same code can be written using async-await style.</span> 13481cb0ef41Sopenharmony_ci(<span class="hljs-keyword">async</span> <span class="hljs-keyword">function</span>(<span class="hljs-params"></span>) { 13491cb0ef41Sopenharmony_ci <span class="hljs-keyword">const</span> addresses = <span class="hljs-keyword">await</span> resolver.<span class="hljs-title function_">resolve4</span>(<span class="hljs-string">'example.org'</span>); 13501cb0ef41Sopenharmony_ci})();</code> <button class="copy-button">copy</button></pre> 13511cb0ef41Sopenharmony_ci<p>The following methods from the <code>dnsPromises</code> API are available:</p> 13521cb0ef41Sopenharmony_ci<ul> 13531cb0ef41Sopenharmony_ci<li><a href="#dnspromisesgetservers"><code>resolver.getServers()</code></a></li> 13541cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvehostname-rrtype"><code>resolver.resolve()</code></a></li> 13551cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolve4hostname-options"><code>resolver.resolve4()</code></a></li> 13561cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolve6hostname-options"><code>resolver.resolve6()</code></a></li> 13571cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolveanyhostname"><code>resolver.resolveAny()</code></a></li> 13581cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvecaahostname"><code>resolver.resolveCaa()</code></a></li> 13591cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvecnamehostname"><code>resolver.resolveCname()</code></a></li> 13601cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvemxhostname"><code>resolver.resolveMx()</code></a></li> 13611cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvenaptrhostname"><code>resolver.resolveNaptr()</code></a></li> 13621cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvenshostname"><code>resolver.resolveNs()</code></a></li> 13631cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolveptrhostname"><code>resolver.resolvePtr()</code></a></li> 13641cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvesoahostname"><code>resolver.resolveSoa()</code></a></li> 13651cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvesrvhostname"><code>resolver.resolveSrv()</code></a></li> 13661cb0ef41Sopenharmony_ci<li><a href="#dnspromisesresolvetxthostname"><code>resolver.resolveTxt()</code></a></li> 13671cb0ef41Sopenharmony_ci<li><a href="#dnspromisesreverseip"><code>resolver.reverse()</code></a></li> 13681cb0ef41Sopenharmony_ci<li><a href="#dnspromisessetserversservers"><code>resolver.setServers()</code></a></li> 13691cb0ef41Sopenharmony_ci</ul> 13701cb0ef41Sopenharmony_ci<h4><code>resolver.cancel()</code><span><a class="mark" href="#resolvercancel_1" id="resolvercancel_1">#</a></span><a aria-hidden="true" class="legacy" id="dns_resolver_cancel_1"></a></h4> 13711cb0ef41Sopenharmony_ci<div class="api_metadata"> 13721cb0ef41Sopenharmony_ci<span>Added in: v15.3.0, v14.17.0</span> 13731cb0ef41Sopenharmony_ci</div> 13741cb0ef41Sopenharmony_ci<p>Cancel all outstanding DNS queries made by this resolver. The corresponding 13751cb0ef41Sopenharmony_cipromises will be rejected with an error with the code <code>ECANCELLED</code>.</p> 13761cb0ef41Sopenharmony_ci<h4><code>dnsPromises.getServers()</code><span><a class="mark" href="#dnspromisesgetservers" id="dnspromisesgetservers">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_getservers"></a></h4> 13771cb0ef41Sopenharmony_ci<div class="api_metadata"> 13781cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 13791cb0ef41Sopenharmony_ci</div> 13801cb0ef41Sopenharmony_ci<ul> 13811cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></li> 13821cb0ef41Sopenharmony_ci</ul> 13831cb0ef41Sopenharmony_ci<p>Returns an array of IP address strings, formatted according to <a href="https://tools.ietf.org/html/rfc5952#section-6">RFC 5952</a>, 13841cb0ef41Sopenharmony_cithat are currently configured for DNS resolution. A string will include a port 13851cb0ef41Sopenharmony_cisection if a custom port is used.</p> 13861cb0ef41Sopenharmony_ci<!-- eslint-disable semi--> 13871cb0ef41Sopenharmony_ci<pre><code class="language-js">[ 13881cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4'</span>, 13891cb0ef41Sopenharmony_ci <span class="hljs-string">'2001:4860:4860::8888'</span>, 13901cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4:1053'</span>, 13911cb0ef41Sopenharmony_ci <span class="hljs-string">'[2001:4860:4860::8888]:1053'</span>, 13921cb0ef41Sopenharmony_ci]</code> <button class="copy-button">copy</button></pre> 13931cb0ef41Sopenharmony_ci<h4><code>dnsPromises.lookup(hostname[, options])</code><span><a class="mark" href="#dnspromiseslookuphostname-options" id="dnspromiseslookuphostname-options">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_lookup_hostname_options"></a></h4> 13941cb0ef41Sopenharmony_ci<div class="api_metadata"> 13951cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 13961cb0ef41Sopenharmony_ci</div> 13971cb0ef41Sopenharmony_ci<ul> 13981cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 13991cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 14001cb0ef41Sopenharmony_ci<ul> 14011cb0ef41Sopenharmony_ci<li><code>family</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The record family. Must be <code>4</code>, <code>6</code>, or <code>0</code>. The value 14021cb0ef41Sopenharmony_ci<code>0</code> indicates that IPv4 and IPv6 addresses are both returned. <strong>Default:</strong> 14031cb0ef41Sopenharmony_ci<code>0</code>.</li> 14041cb0ef41Sopenharmony_ci<li><code>hints</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> One or more <a href="#supported-getaddrinfo-flags">supported <code>getaddrinfo</code> flags</a>. Multiple 14051cb0ef41Sopenharmony_ciflags may be passed by bitwise <code>OR</code>ing their values.</li> 14061cb0ef41Sopenharmony_ci<li><code>all</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> When <code>true</code>, the <code>Promise</code> is resolved with all addresses in 14071cb0ef41Sopenharmony_cian array. Otherwise, returns a single address. <strong>Default:</strong> <code>false</code>.</li> 14081cb0ef41Sopenharmony_ci<li><code>verbatim</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> When <code>true</code>, the <code>Promise</code> is resolved with IPv4 and 14091cb0ef41Sopenharmony_ciIPv6 addresses in the order the DNS resolver returned them. When <code>false</code>, 14101cb0ef41Sopenharmony_ciIPv4 addresses are placed before IPv6 addresses. 14111cb0ef41Sopenharmony_ci<strong>Default:</strong> currently <code>false</code> (addresses are reordered) but this is 14121cb0ef41Sopenharmony_ciexpected to change in the not too distant future. Default value is 14131cb0ef41Sopenharmony_ciconfigurable using <a href="#dnssetdefaultresultorderorder"><code>dns.setDefaultResultOrder()</code></a> or 14141cb0ef41Sopenharmony_ci<a href="cli.html#--dns-result-orderorder"><code>--dns-result-order</code></a>. New code should use <code>{ verbatim: true }</code>.</li> 14151cb0ef41Sopenharmony_ci</ul> 14161cb0ef41Sopenharmony_ci</li> 14171cb0ef41Sopenharmony_ci</ul> 14181cb0ef41Sopenharmony_ci<p>Resolves a host name (e.g. <code>'nodejs.org'</code>) into the first found A (IPv4) or 14191cb0ef41Sopenharmony_ciAAAA (IPv6) record. All <code>option</code> properties are optional. If <code>options</code> is an 14201cb0ef41Sopenharmony_ciinteger, then it must be <code>4</code> or <code>6</code> – if <code>options</code> is not provided, then IPv4 14211cb0ef41Sopenharmony_ciand IPv6 addresses are both returned if found.</p> 14221cb0ef41Sopenharmony_ci<p>With the <code>all</code> option set to <code>true</code>, the <code>Promise</code> is resolved with <code>addresses</code> 14231cb0ef41Sopenharmony_cibeing an array of objects with the properties <code>address</code> and <code>family</code>.</p> 14241cb0ef41Sopenharmony_ci<p>On error, the <code>Promise</code> is rejected with an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> 14251cb0ef41Sopenharmony_ciis the error code. 14261cb0ef41Sopenharmony_ciKeep in mind that <code>err.code</code> will be set to <code>'ENOTFOUND'</code> not only when 14271cb0ef41Sopenharmony_cithe host name does not exist but also when the lookup fails in other ways 14281cb0ef41Sopenharmony_cisuch as no available file descriptors.</p> 14291cb0ef41Sopenharmony_ci<p><a href="#dnspromiseslookuphostname-options"><code>dnsPromises.lookup()</code></a> does not necessarily have anything to do with the DNS 14301cb0ef41Sopenharmony_ciprotocol. The implementation uses an operating system facility that can 14311cb0ef41Sopenharmony_ciassociate names with addresses and vice versa. This implementation can have 14321cb0ef41Sopenharmony_cisubtle but important consequences on the behavior of any Node.js program. Please 14331cb0ef41Sopenharmony_citake some time to consult the <a href="#implementation-considerations">Implementation considerations section</a> before 14341cb0ef41Sopenharmony_ciusing <code>dnsPromises.lookup()</code>.</p> 14351cb0ef41Sopenharmony_ci<p>Example usage:</p> 14361cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> dns = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>); 14371cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> dnsPromises = dns.<span class="hljs-property">promises</span>; 14381cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> options = { 14391cb0ef41Sopenharmony_ci <span class="hljs-attr">family</span>: <span class="hljs-number">6</span>, 14401cb0ef41Sopenharmony_ci <span class="hljs-attr">hints</span>: dns.<span class="hljs-property">ADDRCONFIG</span> | dns.<span class="hljs-property">V4MAPPED</span>, 14411cb0ef41Sopenharmony_ci}; 14421cb0ef41Sopenharmony_ci 14431cb0ef41Sopenharmony_cidnsPromises.<span class="hljs-title function_">lookup</span>(<span class="hljs-string">'example.com'</span>, options).<span class="hljs-title function_">then</span>(<span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { 14441cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'address: %j family: IPv%s'</span>, result.<span class="hljs-property">address</span>, result.<span class="hljs-property">family</span>); 14451cb0ef41Sopenharmony_ci <span class="hljs-comment">// address: "2606:2800:220:1:248:1893:25c8:1946" family: IPv6</span> 14461cb0ef41Sopenharmony_ci}); 14471cb0ef41Sopenharmony_ci 14481cb0ef41Sopenharmony_ci<span class="hljs-comment">// When options.all is true, the result will be an Array.</span> 14491cb0ef41Sopenharmony_cioptions.<span class="hljs-property">all</span> = <span class="hljs-literal">true</span>; 14501cb0ef41Sopenharmony_cidnsPromises.<span class="hljs-title function_">lookup</span>(<span class="hljs-string">'example.com'</span>, options).<span class="hljs-title function_">then</span>(<span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { 14511cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'addresses: %j'</span>, result); 14521cb0ef41Sopenharmony_ci <span class="hljs-comment">// addresses: [{"address":"2606:2800:220:1:248:1893:25c8:1946","family":6}]</span> 14531cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre> 14541cb0ef41Sopenharmony_ci<h4><code>dnsPromises.lookupService(address, port)</code><span><a class="mark" href="#dnspromiseslookupserviceaddress-port" id="dnspromiseslookupserviceaddress-port">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_lookupservice_address_port"></a></h4> 14551cb0ef41Sopenharmony_ci<div class="api_metadata"> 14561cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 14571cb0ef41Sopenharmony_ci</div> 14581cb0ef41Sopenharmony_ci<ul> 14591cb0ef41Sopenharmony_ci<li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 14601cb0ef41Sopenharmony_ci<li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a></li> 14611cb0ef41Sopenharmony_ci</ul> 14621cb0ef41Sopenharmony_ci<p>Resolves the given <code>address</code> and <code>port</code> into a host name and service using 14631cb0ef41Sopenharmony_cithe operating system's underlying <code>getnameinfo</code> implementation.</p> 14641cb0ef41Sopenharmony_ci<p>If <code>address</code> is not a valid IP address, a <code>TypeError</code> will be thrown. 14651cb0ef41Sopenharmony_ciThe <code>port</code> will be coerced to a number. If it is not a legal port, a <code>TypeError</code> 14661cb0ef41Sopenharmony_ciwill be thrown.</p> 14671cb0ef41Sopenharmony_ci<p>On error, the <code>Promise</code> is rejected with an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> 14681cb0ef41Sopenharmony_ciis the error code.</p> 14691cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> dnsPromises = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:dns'</span>).<span class="hljs-property">promises</span>; 14701cb0ef41Sopenharmony_cidnsPromises.<span class="hljs-title function_">lookupService</span>(<span class="hljs-string">'127.0.0.1'</span>, <span class="hljs-number">22</span>).<span class="hljs-title function_">then</span>(<span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { 14711cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(result.<span class="hljs-property">hostname</span>, result.<span class="hljs-property">service</span>); 14721cb0ef41Sopenharmony_ci <span class="hljs-comment">// Prints: localhost ssh</span> 14731cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre> 14741cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolve(hostname[, rrtype])</code><span><a class="mark" href="#dnspromisesresolvehostname-rrtype" id="dnspromisesresolvehostname-rrtype">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolve_hostname_rrtype"></a></h4> 14751cb0ef41Sopenharmony_ci<div class="api_metadata"> 14761cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 14771cb0ef41Sopenharmony_ci</div> 14781cb0ef41Sopenharmony_ci<ul> 14791cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host name to resolve.</li> 14801cb0ef41Sopenharmony_ci<li><code>rrtype</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Resource record type. <strong>Default:</strong> <code>'A'</code>.</li> 14811cb0ef41Sopenharmony_ci</ul> 14821cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve a host name (e.g. <code>'nodejs.org'</code>) into an array 14831cb0ef41Sopenharmony_ciof the resource records. When successful, the <code>Promise</code> is resolved with an 14841cb0ef41Sopenharmony_ciarray of resource records. The type and structure of individual results vary 14851cb0ef41Sopenharmony_cibased on <code>rrtype</code>:</p> 14861cb0ef41Sopenharmony_ci 14871cb0ef41Sopenharmony_ci 14881cb0ef41Sopenharmony_ci 14891cb0ef41Sopenharmony_ci 14901cb0ef41Sopenharmony_ci 14911cb0ef41Sopenharmony_ci 14921cb0ef41Sopenharmony_ci 14931cb0ef41Sopenharmony_ci 14941cb0ef41Sopenharmony_ci 14951cb0ef41Sopenharmony_ci 14961cb0ef41Sopenharmony_ci 14971cb0ef41Sopenharmony_ci 14981cb0ef41Sopenharmony_ci 14991cb0ef41Sopenharmony_ci 15001cb0ef41Sopenharmony_ci 15011cb0ef41Sopenharmony_ci 15021cb0ef41Sopenharmony_ci 15031cb0ef41Sopenharmony_ci 15041cb0ef41Sopenharmony_ci 15051cb0ef41Sopenharmony_ci 15061cb0ef41Sopenharmony_ci 15071cb0ef41Sopenharmony_ci 15081cb0ef41Sopenharmony_ci 15091cb0ef41Sopenharmony_ci 15101cb0ef41Sopenharmony_ci 15111cb0ef41Sopenharmony_ci 15121cb0ef41Sopenharmony_ci 15131cb0ef41Sopenharmony_ci 15141cb0ef41Sopenharmony_ci 15151cb0ef41Sopenharmony_ci 15161cb0ef41Sopenharmony_ci 15171cb0ef41Sopenharmony_ci 15181cb0ef41Sopenharmony_ci 15191cb0ef41Sopenharmony_ci 15201cb0ef41Sopenharmony_ci 15211cb0ef41Sopenharmony_ci 15221cb0ef41Sopenharmony_ci 15231cb0ef41Sopenharmony_ci 15241cb0ef41Sopenharmony_ci 15251cb0ef41Sopenharmony_ci 15261cb0ef41Sopenharmony_ci 15271cb0ef41Sopenharmony_ci 15281cb0ef41Sopenharmony_ci 15291cb0ef41Sopenharmony_ci 15301cb0ef41Sopenharmony_ci 15311cb0ef41Sopenharmony_ci 15321cb0ef41Sopenharmony_ci 15331cb0ef41Sopenharmony_ci 15341cb0ef41Sopenharmony_ci 15351cb0ef41Sopenharmony_ci 15361cb0ef41Sopenharmony_ci 15371cb0ef41Sopenharmony_ci 15381cb0ef41Sopenharmony_ci 15391cb0ef41Sopenharmony_ci 15401cb0ef41Sopenharmony_ci 15411cb0ef41Sopenharmony_ci 15421cb0ef41Sopenharmony_ci 15431cb0ef41Sopenharmony_ci 15441cb0ef41Sopenharmony_ci 15451cb0ef41Sopenharmony_ci 15461cb0ef41Sopenharmony_ci 15471cb0ef41Sopenharmony_ci 15481cb0ef41Sopenharmony_ci 15491cb0ef41Sopenharmony_ci 15501cb0ef41Sopenharmony_ci 15511cb0ef41Sopenharmony_ci 15521cb0ef41Sopenharmony_ci 15531cb0ef41Sopenharmony_ci 15541cb0ef41Sopenharmony_ci 15551cb0ef41Sopenharmony_ci 15561cb0ef41Sopenharmony_ci 15571cb0ef41Sopenharmony_ci 15581cb0ef41Sopenharmony_ci 15591cb0ef41Sopenharmony_ci 15601cb0ef41Sopenharmony_ci 15611cb0ef41Sopenharmony_ci 15621cb0ef41Sopenharmony_ci 15631cb0ef41Sopenharmony_ci 15641cb0ef41Sopenharmony_ci 15651cb0ef41Sopenharmony_ci 15661cb0ef41Sopenharmony_ci 15671cb0ef41Sopenharmony_ci 15681cb0ef41Sopenharmony_ci 15691cb0ef41Sopenharmony_ci<table><thead><tr><th><code>rrtype</code></th><th><code>records</code> contains</th><th>Result type</th><th>Shorthand method</th></tr></thead><tbody><tr><td><code>'A'</code></td><td>IPv4 addresses (default)</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnspromisesresolve4hostname-options"><code>dnsPromises.resolve4()</code></a></td></tr><tr><td><code>'AAAA'</code></td><td>IPv6 addresses</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnspromisesresolve6hostname-options"><code>dnsPromises.resolve6()</code></a></td></tr><tr><td><code>'ANY'</code></td><td>any records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnspromisesresolveanyhostname"><code>dnsPromises.resolveAny()</code></a></td></tr><tr><td><code>'CAA'</code></td><td>CA authorization records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnspromisesresolvecaahostname"><code>dnsPromises.resolveCaa()</code></a></td></tr><tr><td><code>'CNAME'</code></td><td>canonical name records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnspromisesresolvecnamehostname"><code>dnsPromises.resolveCname()</code></a></td></tr><tr><td><code>'MX'</code></td><td>mail exchange records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnspromisesresolvemxhostname"><code>dnsPromises.resolveMx()</code></a></td></tr><tr><td><code>'NAPTR'</code></td><td>name authority pointer records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnspromisesresolvenaptrhostname"><code>dnsPromises.resolveNaptr()</code></a></td></tr><tr><td><code>'NS'</code></td><td>name server records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnspromisesresolvenshostname"><code>dnsPromises.resolveNs()</code></a></td></tr><tr><td><code>'PTR'</code></td><td>pointer records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></td><td><a href="#dnspromisesresolveptrhostname"><code>dnsPromises.resolvePtr()</code></a></td></tr><tr><td><code>'SOA'</code></td><td>start of authority records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnspromisesresolvesoahostname"><code>dnsPromises.resolveSoa()</code></a></td></tr><tr><td><code>'SRV'</code></td><td>service records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></td><td><a href="#dnspromisesresolvesrvhostname"><code>dnsPromises.resolveSrv()</code></a></td></tr><tr><td><code>'TXT'</code></td><td>text records</td><td><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a></td><td><a href="#dnspromisesresolvetxthostname"><code>dnsPromises.resolveTxt()</code></a></td></tr></tbody></table> 15701cb0ef41Sopenharmony_ci<p>On error, the <code>Promise</code> is rejected with an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> 15711cb0ef41Sopenharmony_ciis one of the <a href="#error-codes">DNS error codes</a>.</p> 15721cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolve4(hostname[, options])</code><span><a class="mark" href="#dnspromisesresolve4hostname-options" id="dnspromisesresolve4hostname-options">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolve4_hostname_options"></a></h4> 15731cb0ef41Sopenharmony_ci<div class="api_metadata"> 15741cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 15751cb0ef41Sopenharmony_ci</div> 15761cb0ef41Sopenharmony_ci<ul> 15771cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host name to resolve.</li> 15781cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 15791cb0ef41Sopenharmony_ci<ul> 15801cb0ef41Sopenharmony_ci<li><code>ttl</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> Retrieve the Time-To-Live value (TTL) of each record. 15811cb0ef41Sopenharmony_ciWhen <code>true</code>, the <code>Promise</code> is resolved with an array of 15821cb0ef41Sopenharmony_ci<code>{ address: '1.2.3.4', ttl: 60 }</code> objects rather than an array of strings, 15831cb0ef41Sopenharmony_ciwith the TTL expressed in seconds.</li> 15841cb0ef41Sopenharmony_ci</ul> 15851cb0ef41Sopenharmony_ci</li> 15861cb0ef41Sopenharmony_ci</ul> 15871cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve IPv4 addresses (<code>A</code> records) for the 15881cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with an array of IPv4 15891cb0ef41Sopenharmony_ciaddresses (e.g. <code>['74.125.79.104', '74.125.79.105', '74.125.79.106']</code>).</p> 15901cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolve6(hostname[, options])</code><span><a class="mark" href="#dnspromisesresolve6hostname-options" id="dnspromisesresolve6hostname-options">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolve6_hostname_options"></a></h4> 15911cb0ef41Sopenharmony_ci<div class="api_metadata"> 15921cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 15931cb0ef41Sopenharmony_ci</div> 15941cb0ef41Sopenharmony_ci<ul> 15951cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host name to resolve.</li> 15961cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> 15971cb0ef41Sopenharmony_ci<ul> 15981cb0ef41Sopenharmony_ci<li><code>ttl</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> Retrieve the Time-To-Live value (TTL) of each record. 15991cb0ef41Sopenharmony_ciWhen <code>true</code>, the <code>Promise</code> is resolved with an array of 16001cb0ef41Sopenharmony_ci<code>{ address: '0:1:2:3:4:5:6:7', ttl: 60 }</code> objects rather than an array of 16011cb0ef41Sopenharmony_cistrings, with the TTL expressed in seconds.</li> 16021cb0ef41Sopenharmony_ci</ul> 16031cb0ef41Sopenharmony_ci</li> 16041cb0ef41Sopenharmony_ci</ul> 16051cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve IPv6 addresses (<code>AAAA</code> records) for the 16061cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with an array of IPv6 16071cb0ef41Sopenharmony_ciaddresses.</p> 16081cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveAny(hostname)</code><span><a class="mark" href="#dnspromisesresolveanyhostname" id="dnspromisesresolveanyhostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolveany_hostname"></a></h4> 16091cb0ef41Sopenharmony_ci<div class="api_metadata"> 16101cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 16111cb0ef41Sopenharmony_ci</div> 16121cb0ef41Sopenharmony_ci<ul> 16131cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 16141cb0ef41Sopenharmony_ci</ul> 16151cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve all records (also known as <code>ANY</code> or <code>*</code> query). 16161cb0ef41Sopenharmony_ciOn success, the <code>Promise</code> is resolved with an array containing various types of 16171cb0ef41Sopenharmony_cirecords. Each object has a property <code>type</code> that indicates the type of the 16181cb0ef41Sopenharmony_cicurrent record. And depending on the <code>type</code>, additional properties will be 16191cb0ef41Sopenharmony_cipresent on the object:</p> 16201cb0ef41Sopenharmony_ci 16211cb0ef41Sopenharmony_ci 16221cb0ef41Sopenharmony_ci 16231cb0ef41Sopenharmony_ci 16241cb0ef41Sopenharmony_ci 16251cb0ef41Sopenharmony_ci 16261cb0ef41Sopenharmony_ci 16271cb0ef41Sopenharmony_ci 16281cb0ef41Sopenharmony_ci 16291cb0ef41Sopenharmony_ci 16301cb0ef41Sopenharmony_ci 16311cb0ef41Sopenharmony_ci 16321cb0ef41Sopenharmony_ci 16331cb0ef41Sopenharmony_ci 16341cb0ef41Sopenharmony_ci 16351cb0ef41Sopenharmony_ci 16361cb0ef41Sopenharmony_ci 16371cb0ef41Sopenharmony_ci 16381cb0ef41Sopenharmony_ci 16391cb0ef41Sopenharmony_ci 16401cb0ef41Sopenharmony_ci 16411cb0ef41Sopenharmony_ci 16421cb0ef41Sopenharmony_ci 16431cb0ef41Sopenharmony_ci 16441cb0ef41Sopenharmony_ci 16451cb0ef41Sopenharmony_ci 16461cb0ef41Sopenharmony_ci 16471cb0ef41Sopenharmony_ci 16481cb0ef41Sopenharmony_ci 16491cb0ef41Sopenharmony_ci 16501cb0ef41Sopenharmony_ci 16511cb0ef41Sopenharmony_ci 16521cb0ef41Sopenharmony_ci 16531cb0ef41Sopenharmony_ci 16541cb0ef41Sopenharmony_ci 16551cb0ef41Sopenharmony_ci 16561cb0ef41Sopenharmony_ci 16571cb0ef41Sopenharmony_ci 16581cb0ef41Sopenharmony_ci 16591cb0ef41Sopenharmony_ci 16601cb0ef41Sopenharmony_ci 16611cb0ef41Sopenharmony_ci 16621cb0ef41Sopenharmony_ci 16631cb0ef41Sopenharmony_ci 16641cb0ef41Sopenharmony_ci 16651cb0ef41Sopenharmony_ci 16661cb0ef41Sopenharmony_ci 16671cb0ef41Sopenharmony_ci 16681cb0ef41Sopenharmony_ci 16691cb0ef41Sopenharmony_ci<table><thead><tr><th>Type</th><th>Properties</th></tr></thead><tbody><tr><td><code>'A'</code></td><td><code>address</code>/<code>ttl</code></td></tr><tr><td><code>'AAAA'</code></td><td><code>address</code>/<code>ttl</code></td></tr><tr><td><code>'CNAME'</code></td><td><code>value</code></td></tr><tr><td><code>'MX'</code></td><td>Refer to <a href="#dnspromisesresolvemxhostname"><code>dnsPromises.resolveMx()</code></a></td></tr><tr><td><code>'NAPTR'</code></td><td>Refer to <a href="#dnspromisesresolvenaptrhostname"><code>dnsPromises.resolveNaptr()</code></a></td></tr><tr><td><code>'NS'</code></td><td><code>value</code></td></tr><tr><td><code>'PTR'</code></td><td><code>value</code></td></tr><tr><td><code>'SOA'</code></td><td>Refer to <a href="#dnspromisesresolvesoahostname"><code>dnsPromises.resolveSoa()</code></a></td></tr><tr><td><code>'SRV'</code></td><td>Refer to <a href="#dnspromisesresolvesrvhostname"><code>dnsPromises.resolveSrv()</code></a></td></tr><tr><td><code>'TXT'</code></td><td>This type of record contains an array property called <code>entries</code> which refers to <a href="#dnspromisesresolvetxthostname"><code>dnsPromises.resolveTxt()</code></a>, e.g. <code>{ entries: ['...'], type: 'TXT' }</code></td></tr></tbody></table> 16701cb0ef41Sopenharmony_ci<p>Here is an example of the result object:</p> 16711cb0ef41Sopenharmony_ci<!-- eslint-disable semi --> 16721cb0ef41Sopenharmony_ci<pre><code class="language-js">[ { <span class="hljs-attr">type</span>: <span class="hljs-string">'A'</span>, <span class="hljs-attr">address</span>: <span class="hljs-string">'127.0.0.1'</span>, <span class="hljs-attr">ttl</span>: <span class="hljs-number">299</span> }, 16731cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'CNAME'</span>, <span class="hljs-attr">value</span>: <span class="hljs-string">'example.com'</span> }, 16741cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'MX'</span>, <span class="hljs-attr">exchange</span>: <span class="hljs-string">'alt4.aspmx.l.example.com'</span>, <span class="hljs-attr">priority</span>: <span class="hljs-number">50</span> }, 16751cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'NS'</span>, <span class="hljs-attr">value</span>: <span class="hljs-string">'ns1.example.com'</span> }, 16761cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'TXT'</span>, <span class="hljs-attr">entries</span>: [ <span class="hljs-string">'v=spf1 include:_spf.example.com ~all'</span> ] }, 16771cb0ef41Sopenharmony_ci { <span class="hljs-attr">type</span>: <span class="hljs-string">'SOA'</span>, 16781cb0ef41Sopenharmony_ci <span class="hljs-attr">nsname</span>: <span class="hljs-string">'ns1.example.com'</span>, 16791cb0ef41Sopenharmony_ci <span class="hljs-attr">hostmaster</span>: <span class="hljs-string">'admin.example.com'</span>, 16801cb0ef41Sopenharmony_ci <span class="hljs-attr">serial</span>: <span class="hljs-number">156696742</span>, 16811cb0ef41Sopenharmony_ci <span class="hljs-attr">refresh</span>: <span class="hljs-number">900</span>, 16821cb0ef41Sopenharmony_ci <span class="hljs-attr">retry</span>: <span class="hljs-number">900</span>, 16831cb0ef41Sopenharmony_ci <span class="hljs-attr">expire</span>: <span class="hljs-number">1800</span>, 16841cb0ef41Sopenharmony_ci <span class="hljs-attr">minttl</span>: <span class="hljs-number">60</span> } ]</code> <button class="copy-button">copy</button></pre> 16851cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveCaa(hostname)</code><span><a class="mark" href="#dnspromisesresolvecaahostname" id="dnspromisesresolvecaahostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvecaa_hostname"></a></h4> 16861cb0ef41Sopenharmony_ci<div class="api_metadata"> 16871cb0ef41Sopenharmony_ci<span>Added in: v15.0.0, v14.17.0</span> 16881cb0ef41Sopenharmony_ci</div> 16891cb0ef41Sopenharmony_ci<ul> 16901cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 16911cb0ef41Sopenharmony_ci</ul> 16921cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve <code>CAA</code> records for the <code>hostname</code>. On success, 16931cb0ef41Sopenharmony_cithe <code>Promise</code> is resolved with an array of objects containing available 16941cb0ef41Sopenharmony_cicertification authority authorization records available for the <code>hostname</code> 16951cb0ef41Sopenharmony_ci(e.g. <code>[{critical: 0, iodef: 'mailto:pki@example.com'},{critical: 128, issue: 'pki.example.com'}]</code>).</p> 16961cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveCname(hostname)</code><span><a class="mark" href="#dnspromisesresolvecnamehostname" id="dnspromisesresolvecnamehostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvecname_hostname"></a></h4> 16971cb0ef41Sopenharmony_ci<div class="api_metadata"> 16981cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 16991cb0ef41Sopenharmony_ci</div> 17001cb0ef41Sopenharmony_ci<ul> 17011cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 17021cb0ef41Sopenharmony_ci</ul> 17031cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve <code>CNAME</code> records for the <code>hostname</code>. On success, 17041cb0ef41Sopenharmony_cithe <code>Promise</code> is resolved with an array of canonical name records available for 17051cb0ef41Sopenharmony_cithe <code>hostname</code> (e.g. <code>['bar.example.com']</code>).</p> 17061cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveMx(hostname)</code><span><a class="mark" href="#dnspromisesresolvemxhostname" id="dnspromisesresolvemxhostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvemx_hostname"></a></h4> 17071cb0ef41Sopenharmony_ci<div class="api_metadata"> 17081cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 17091cb0ef41Sopenharmony_ci</div> 17101cb0ef41Sopenharmony_ci<ul> 17111cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 17121cb0ef41Sopenharmony_ci</ul> 17131cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve mail exchange records (<code>MX</code> records) for the 17141cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with an array of objects 17151cb0ef41Sopenharmony_cicontaining both a <code>priority</code> and <code>exchange</code> property (e.g. 17161cb0ef41Sopenharmony_ci<code>[{priority: 10, exchange: 'mx.example.com'}, ...]</code>).</p> 17171cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveNaptr(hostname)</code><span><a class="mark" href="#dnspromisesresolvenaptrhostname" id="dnspromisesresolvenaptrhostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvenaptr_hostname"></a></h4> 17181cb0ef41Sopenharmony_ci<div class="api_metadata"> 17191cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 17201cb0ef41Sopenharmony_ci</div> 17211cb0ef41Sopenharmony_ci<ul> 17221cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 17231cb0ef41Sopenharmony_ci</ul> 17241cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve regular expression-based records (<code>NAPTR</code> 17251cb0ef41Sopenharmony_cirecords) for the <code>hostname</code>. On success, the <code>Promise</code> is resolved with an array 17261cb0ef41Sopenharmony_ciof objects with the following properties:</p> 17271cb0ef41Sopenharmony_ci<ul> 17281cb0ef41Sopenharmony_ci<li><code>flags</code></li> 17291cb0ef41Sopenharmony_ci<li><code>service</code></li> 17301cb0ef41Sopenharmony_ci<li><code>regexp</code></li> 17311cb0ef41Sopenharmony_ci<li><code>replacement</code></li> 17321cb0ef41Sopenharmony_ci<li><code>order</code></li> 17331cb0ef41Sopenharmony_ci<li><code>preference</code></li> 17341cb0ef41Sopenharmony_ci</ul> 17351cb0ef41Sopenharmony_ci<!-- eslint-skip --> 17361cb0ef41Sopenharmony_ci<pre><code class="language-js">{ 17371cb0ef41Sopenharmony_ci <span class="hljs-attr">flags</span>: <span class="hljs-string">'s'</span>, 17381cb0ef41Sopenharmony_ci <span class="hljs-attr">service</span>: <span class="hljs-string">'SIP+D2U'</span>, 17391cb0ef41Sopenharmony_ci <span class="hljs-attr">regexp</span>: <span class="hljs-string">''</span>, 17401cb0ef41Sopenharmony_ci <span class="hljs-attr">replacement</span>: <span class="hljs-string">'_sip._udp.example.com'</span>, 17411cb0ef41Sopenharmony_ci <span class="hljs-attr">order</span>: <span class="hljs-number">30</span>, 17421cb0ef41Sopenharmony_ci <span class="hljs-attr">preference</span>: <span class="hljs-number">100</span> 17431cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre> 17441cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveNs(hostname)</code><span><a class="mark" href="#dnspromisesresolvenshostname" id="dnspromisesresolvenshostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvens_hostname"></a></h4> 17451cb0ef41Sopenharmony_ci<div class="api_metadata"> 17461cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 17471cb0ef41Sopenharmony_ci</div> 17481cb0ef41Sopenharmony_ci<ul> 17491cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 17501cb0ef41Sopenharmony_ci</ul> 17511cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve name server records (<code>NS</code> records) for the 17521cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with an array of name server 17531cb0ef41Sopenharmony_cirecords available for <code>hostname</code> (e.g. 17541cb0ef41Sopenharmony_ci<code>['ns1.example.com', 'ns2.example.com']</code>).</p> 17551cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolvePtr(hostname)</code><span><a class="mark" href="#dnspromisesresolveptrhostname" id="dnspromisesresolveptrhostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolveptr_hostname"></a></h4> 17561cb0ef41Sopenharmony_ci<div class="api_metadata"> 17571cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 17581cb0ef41Sopenharmony_ci</div> 17591cb0ef41Sopenharmony_ci<ul> 17601cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 17611cb0ef41Sopenharmony_ci</ul> 17621cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve pointer records (<code>PTR</code> records) for the 17631cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with an array of strings 17641cb0ef41Sopenharmony_cicontaining the reply records.</p> 17651cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveSoa(hostname)</code><span><a class="mark" href="#dnspromisesresolvesoahostname" id="dnspromisesresolvesoahostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvesoa_hostname"></a></h4> 17661cb0ef41Sopenharmony_ci<div class="api_metadata"> 17671cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 17681cb0ef41Sopenharmony_ci</div> 17691cb0ef41Sopenharmony_ci<ul> 17701cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 17711cb0ef41Sopenharmony_ci</ul> 17721cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve a start of authority record (<code>SOA</code> record) for 17731cb0ef41Sopenharmony_cithe <code>hostname</code>. On success, the <code>Promise</code> is resolved with an object with the 17741cb0ef41Sopenharmony_cifollowing properties:</p> 17751cb0ef41Sopenharmony_ci<ul> 17761cb0ef41Sopenharmony_ci<li><code>nsname</code></li> 17771cb0ef41Sopenharmony_ci<li><code>hostmaster</code></li> 17781cb0ef41Sopenharmony_ci<li><code>serial</code></li> 17791cb0ef41Sopenharmony_ci<li><code>refresh</code></li> 17801cb0ef41Sopenharmony_ci<li><code>retry</code></li> 17811cb0ef41Sopenharmony_ci<li><code>expire</code></li> 17821cb0ef41Sopenharmony_ci<li><code>minttl</code></li> 17831cb0ef41Sopenharmony_ci</ul> 17841cb0ef41Sopenharmony_ci<!-- eslint-skip --> 17851cb0ef41Sopenharmony_ci<pre><code class="language-js">{ 17861cb0ef41Sopenharmony_ci <span class="hljs-attr">nsname</span>: <span class="hljs-string">'ns.example.com'</span>, 17871cb0ef41Sopenharmony_ci <span class="hljs-attr">hostmaster</span>: <span class="hljs-string">'root.example.com'</span>, 17881cb0ef41Sopenharmony_ci <span class="hljs-attr">serial</span>: <span class="hljs-number">2013101809</span>, 17891cb0ef41Sopenharmony_ci <span class="hljs-attr">refresh</span>: <span class="hljs-number">10000</span>, 17901cb0ef41Sopenharmony_ci <span class="hljs-attr">retry</span>: <span class="hljs-number">2400</span>, 17911cb0ef41Sopenharmony_ci <span class="hljs-attr">expire</span>: <span class="hljs-number">604800</span>, 17921cb0ef41Sopenharmony_ci <span class="hljs-attr">minttl</span>: <span class="hljs-number">3600</span> 17931cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre> 17941cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveSrv(hostname)</code><span><a class="mark" href="#dnspromisesresolvesrvhostname" id="dnspromisesresolvesrvhostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvesrv_hostname"></a></h4> 17951cb0ef41Sopenharmony_ci<div class="api_metadata"> 17961cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 17971cb0ef41Sopenharmony_ci</div> 17981cb0ef41Sopenharmony_ci<ul> 17991cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 18001cb0ef41Sopenharmony_ci</ul> 18011cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve service records (<code>SRV</code> records) for the 18021cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with an array of objects with 18031cb0ef41Sopenharmony_cithe following properties:</p> 18041cb0ef41Sopenharmony_ci<ul> 18051cb0ef41Sopenharmony_ci<li><code>priority</code></li> 18061cb0ef41Sopenharmony_ci<li><code>weight</code></li> 18071cb0ef41Sopenharmony_ci<li><code>port</code></li> 18081cb0ef41Sopenharmony_ci<li><code>name</code></li> 18091cb0ef41Sopenharmony_ci</ul> 18101cb0ef41Sopenharmony_ci<!-- eslint-skip --> 18111cb0ef41Sopenharmony_ci<pre><code class="language-js">{ 18121cb0ef41Sopenharmony_ci <span class="hljs-attr">priority</span>: <span class="hljs-number">10</span>, 18131cb0ef41Sopenharmony_ci <span class="hljs-attr">weight</span>: <span class="hljs-number">5</span>, 18141cb0ef41Sopenharmony_ci <span class="hljs-attr">port</span>: <span class="hljs-number">21223</span>, 18151cb0ef41Sopenharmony_ci <span class="hljs-attr">name</span>: <span class="hljs-string">'service.example.com'</span> 18161cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre> 18171cb0ef41Sopenharmony_ci<h4><code>dnsPromises.resolveTxt(hostname)</code><span><a class="mark" href="#dnspromisesresolvetxthostname" id="dnspromisesresolvetxthostname">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_resolvetxt_hostname"></a></h4> 18181cb0ef41Sopenharmony_ci<div class="api_metadata"> 18191cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 18201cb0ef41Sopenharmony_ci</div> 18211cb0ef41Sopenharmony_ci<ul> 18221cb0ef41Sopenharmony_ci<li><code>hostname</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 18231cb0ef41Sopenharmony_ci</ul> 18241cb0ef41Sopenharmony_ci<p>Uses the DNS protocol to resolve text queries (<code>TXT</code> records) for the 18251cb0ef41Sopenharmony_ci<code>hostname</code>. On success, the <code>Promise</code> is resolved with a two-dimensional array 18261cb0ef41Sopenharmony_ciof the text records available for <code>hostname</code> (e.g. 18271cb0ef41Sopenharmony_ci<code>[ ['v=spf1 ip4:0.0.0.0 ', '~all' ] ]</code>). Each sub-array contains TXT chunks of 18281cb0ef41Sopenharmony_cione record. Depending on the use case, these could be either joined together or 18291cb0ef41Sopenharmony_citreated separately.</p> 18301cb0ef41Sopenharmony_ci<h4><code>dnsPromises.reverse(ip)</code><span><a class="mark" href="#dnspromisesreverseip" id="dnspromisesreverseip">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_reverse_ip"></a></h4> 18311cb0ef41Sopenharmony_ci<div class="api_metadata"> 18321cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 18331cb0ef41Sopenharmony_ci</div> 18341cb0ef41Sopenharmony_ci<ul> 18351cb0ef41Sopenharmony_ci<li><code>ip</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 18361cb0ef41Sopenharmony_ci</ul> 18371cb0ef41Sopenharmony_ci<p>Performs a reverse DNS query that resolves an IPv4 or IPv6 address to an 18381cb0ef41Sopenharmony_ciarray of host names.</p> 18391cb0ef41Sopenharmony_ci<p>On error, the <code>Promise</code> is rejected with an <a href="errors.html#class-error"><code>Error</code></a> object, where <code>err.code</code> 18401cb0ef41Sopenharmony_ciis one of the <a href="#error-codes">DNS error codes</a>.</p> 18411cb0ef41Sopenharmony_ci<h4><code>dnsPromises.setDefaultResultOrder(order)</code><span><a class="mark" href="#dnspromisessetdefaultresultorderorder" id="dnspromisessetdefaultresultorderorder">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_setdefaultresultorder_order"></a></h4> 18421cb0ef41Sopenharmony_ci<div class="api_metadata"> 18431cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 18441cb0ef41Sopenharmony_ci<table> 18451cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 18461cb0ef41Sopenharmony_ci<tr><td>v17.0.0</td> 18471cb0ef41Sopenharmony_ci<td><p>Changed default value to <code>verbatim</code>.</p></td></tr> 18481cb0ef41Sopenharmony_ci<tr><td>v16.4.0, v14.18.0</td> 18491cb0ef41Sopenharmony_ci<td><p><span>Added in: v16.4.0, v14.18.0</span></p></td></tr> 18501cb0ef41Sopenharmony_ci</tbody></table> 18511cb0ef41Sopenharmony_ci</details> 18521cb0ef41Sopenharmony_ci</div> 18531cb0ef41Sopenharmony_ci<ul> 18541cb0ef41Sopenharmony_ci<li><code>order</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> must be <code>'ipv4first'</code> or <code>'verbatim'</code>.</li> 18551cb0ef41Sopenharmony_ci</ul> 18561cb0ef41Sopenharmony_ci<p>Set the default value of <code>verbatim</code> in <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> and 18571cb0ef41Sopenharmony_ci<a href="#dnspromiseslookuphostname-options"><code>dnsPromises.lookup()</code></a>. The value could be:</p> 18581cb0ef41Sopenharmony_ci<ul> 18591cb0ef41Sopenharmony_ci<li><code>ipv4first</code>: sets default <code>verbatim</code> <code>false</code>.</li> 18601cb0ef41Sopenharmony_ci<li><code>verbatim</code>: sets default <code>verbatim</code> <code>true</code>.</li> 18611cb0ef41Sopenharmony_ci</ul> 18621cb0ef41Sopenharmony_ci<p>The default is <code>verbatim</code> and <a href="#dnspromisessetdefaultresultorderorder"><code>dnsPromises.setDefaultResultOrder()</code></a> have 18631cb0ef41Sopenharmony_cihigher priority than <a href="cli.html#--dns-result-orderorder"><code>--dns-result-order</code></a>. When using <a href="worker_threads.html">worker threads</a>, 18641cb0ef41Sopenharmony_ci<a href="#dnspromisessetdefaultresultorderorder"><code>dnsPromises.setDefaultResultOrder()</code></a> from the main thread won't affect the 18651cb0ef41Sopenharmony_cidefault dns orders in workers.</p> 18661cb0ef41Sopenharmony_ci<h4><code>dnsPromises.getDefaultResultOrder()</code><span><a class="mark" href="#dnspromisesgetdefaultresultorder" id="dnspromisesgetdefaultresultorder">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_getdefaultresultorder"></a></h4> 18671cb0ef41Sopenharmony_ci<div class="api_metadata"> 18681cb0ef41Sopenharmony_ci<span>Added in: v18.17.0</span> 18691cb0ef41Sopenharmony_ci</div> 18701cb0ef41Sopenharmony_ci<p>Get the value of <code>dnsOrder</code>.</p> 18711cb0ef41Sopenharmony_ci<h4><code>dnsPromises.setServers(servers)</code><span><a class="mark" href="#dnspromisessetserversservers" id="dnspromisessetserversservers">#</a></span><a aria-hidden="true" class="legacy" id="dns_dnspromises_setservers_servers"></a></h4> 18721cb0ef41Sopenharmony_ci<div class="api_metadata"> 18731cb0ef41Sopenharmony_ci<span>Added in: v10.6.0</span> 18741cb0ef41Sopenharmony_ci</div> 18751cb0ef41Sopenharmony_ci<ul> 18761cb0ef41Sopenharmony_ci<li><code>servers</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> array of <a href="https://tools.ietf.org/html/rfc5952#section-6">RFC 5952</a> formatted addresses</li> 18771cb0ef41Sopenharmony_ci</ul> 18781cb0ef41Sopenharmony_ci<p>Sets the IP address and port of servers to be used when performing DNS 18791cb0ef41Sopenharmony_ciresolution. The <code>servers</code> argument is an array of <a href="https://tools.ietf.org/html/rfc5952#section-6">RFC 5952</a> formatted 18801cb0ef41Sopenharmony_ciaddresses. If the port is the IANA default DNS port (53) it can be omitted.</p> 18811cb0ef41Sopenharmony_ci<pre><code class="language-js">dnsPromises.<span class="hljs-title function_">setServers</span>([ 18821cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4'</span>, 18831cb0ef41Sopenharmony_ci <span class="hljs-string">'[2001:4860:4860::8888]'</span>, 18841cb0ef41Sopenharmony_ci <span class="hljs-string">'4.4.4.4:1053'</span>, 18851cb0ef41Sopenharmony_ci <span class="hljs-string">'[2001:4860:4860::8888]:1053'</span>, 18861cb0ef41Sopenharmony_ci]);</code> <button class="copy-button">copy</button></pre> 18871cb0ef41Sopenharmony_ci<p>An error will be thrown if an invalid address is provided.</p> 18881cb0ef41Sopenharmony_ci<p>The <code>dnsPromises.setServers()</code> method must not be called while a DNS query is in 18891cb0ef41Sopenharmony_ciprogress.</p> 18901cb0ef41Sopenharmony_ci<p>This method works much like 18911cb0ef41Sopenharmony_ci<a href="https://man7.org/linux/man-pages/man5/resolv.conf.5.html">resolve.conf</a>. 18921cb0ef41Sopenharmony_ciThat is, if attempting to resolve with the first server provided results in a 18931cb0ef41Sopenharmony_ci<code>NOTFOUND</code> error, the <code>resolve()</code> method will <em>not</em> attempt to resolve with 18941cb0ef41Sopenharmony_cisubsequent servers provided. Fallback DNS servers will only be used if the 18951cb0ef41Sopenharmony_ciearlier ones time out or result in some other error.</p> 18961cb0ef41Sopenharmony_ci</section><section><h3>Error codes<span><a class="mark" href="#error-codes" id="error-codes">#</a></span><a aria-hidden="true" class="legacy" id="dns_error_codes"></a></h3> 18971cb0ef41Sopenharmony_ci<p>Each DNS query can return one of the following error codes:</p> 18981cb0ef41Sopenharmony_ci<ul> 18991cb0ef41Sopenharmony_ci<li><code>dns.NODATA</code>: DNS server returned an answer with no data.</li> 19001cb0ef41Sopenharmony_ci<li><code>dns.FORMERR</code>: DNS server claims query was misformatted.</li> 19011cb0ef41Sopenharmony_ci<li><code>dns.SERVFAIL</code>: DNS server returned general failure.</li> 19021cb0ef41Sopenharmony_ci<li><code>dns.NOTFOUND</code>: Domain name not found.</li> 19031cb0ef41Sopenharmony_ci<li><code>dns.NOTIMP</code>: DNS server does not implement the requested operation.</li> 19041cb0ef41Sopenharmony_ci<li><code>dns.REFUSED</code>: DNS server refused query.</li> 19051cb0ef41Sopenharmony_ci<li><code>dns.BADQUERY</code>: Misformatted DNS query.</li> 19061cb0ef41Sopenharmony_ci<li><code>dns.BADNAME</code>: Misformatted host name.</li> 19071cb0ef41Sopenharmony_ci<li><code>dns.BADFAMILY</code>: Unsupported address family.</li> 19081cb0ef41Sopenharmony_ci<li><code>dns.BADRESP</code>: Misformatted DNS reply.</li> 19091cb0ef41Sopenharmony_ci<li><code>dns.CONNREFUSED</code>: Could not contact DNS servers.</li> 19101cb0ef41Sopenharmony_ci<li><code>dns.TIMEOUT</code>: Timeout while contacting DNS servers.</li> 19111cb0ef41Sopenharmony_ci<li><code>dns.EOF</code>: End of file.</li> 19121cb0ef41Sopenharmony_ci<li><code>dns.FILE</code>: Error reading file.</li> 19131cb0ef41Sopenharmony_ci<li><code>dns.NOMEM</code>: Out of memory.</li> 19141cb0ef41Sopenharmony_ci<li><code>dns.DESTRUCTION</code>: Channel is being destroyed.</li> 19151cb0ef41Sopenharmony_ci<li><code>dns.BADSTR</code>: Misformatted string.</li> 19161cb0ef41Sopenharmony_ci<li><code>dns.BADFLAGS</code>: Illegal flags specified.</li> 19171cb0ef41Sopenharmony_ci<li><code>dns.NONAME</code>: Given host name is not numeric.</li> 19181cb0ef41Sopenharmony_ci<li><code>dns.BADHINTS</code>: Illegal hints flags specified.</li> 19191cb0ef41Sopenharmony_ci<li><code>dns.NOTINITIALIZED</code>: c-ares library initialization not yet performed.</li> 19201cb0ef41Sopenharmony_ci<li><code>dns.LOADIPHLPAPI</code>: Error loading <code>iphlpapi.dll</code>.</li> 19211cb0ef41Sopenharmony_ci<li><code>dns.ADDRGETNETWORKPARAMS</code>: Could not find <code>GetNetworkParams</code> function.</li> 19221cb0ef41Sopenharmony_ci<li><code>dns.CANCELLED</code>: DNS query cancelled.</li> 19231cb0ef41Sopenharmony_ci</ul> 19241cb0ef41Sopenharmony_ci<p>The <code>dnsPromises</code> API also exports the above error codes, e.g., <code>dnsPromises.NODATA</code>.</p> 19251cb0ef41Sopenharmony_ci</section><section><h3>Implementation considerations<span><a class="mark" href="#implementation-considerations" id="implementation-considerations">#</a></span><a aria-hidden="true" class="legacy" id="dns_implementation_considerations"></a></h3> 19261cb0ef41Sopenharmony_ci<p>Although <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> and the various <code>dns.resolve*()/dns.reverse()</code> 19271cb0ef41Sopenharmony_cifunctions have the same goal of associating a network name with a network 19281cb0ef41Sopenharmony_ciaddress (or vice versa), their behavior is quite different. These differences 19291cb0ef41Sopenharmony_cican have subtle but significant consequences on the behavior of Node.js 19301cb0ef41Sopenharmony_ciprograms.</p> 19311cb0ef41Sopenharmony_ci<h4><code>dns.lookup()</code><span><a class="mark" href="#dnslookup" id="dnslookup">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_lookup"></a></h4> 19321cb0ef41Sopenharmony_ci<p>Under the hood, <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> uses the same operating system facilities 19331cb0ef41Sopenharmony_cias most other programs. For instance, <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> will almost always 19341cb0ef41Sopenharmony_ciresolve a given name the same way as the <code>ping</code> command. On most POSIX-like 19351cb0ef41Sopenharmony_cioperating systems, the behavior of the <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> function can be 19361cb0ef41Sopenharmony_cimodified by changing settings in <a href="http://man7.org/linux/man-pages/man5/nsswitch.conf.5.html"><code>nsswitch.conf(5)</code></a> and/or <a href="http://man7.org/linux/man-pages/man5/resolv.conf.5.html"><code>resolv.conf(5)</code></a>, 19371cb0ef41Sopenharmony_cibut changing these files will change the behavior of all other 19381cb0ef41Sopenharmony_ciprograms running on the same operating system.</p> 19391cb0ef41Sopenharmony_ci<p>Though the call to <code>dns.lookup()</code> will be asynchronous from JavaScript's 19401cb0ef41Sopenharmony_ciperspective, it is implemented as a synchronous call to <a href="http://man7.org/linux/man-pages/man3/getaddrinfo.3.html"><code>getaddrinfo(3)</code></a> that runs 19411cb0ef41Sopenharmony_cion libuv's threadpool. This can have surprising negative performance 19421cb0ef41Sopenharmony_ciimplications for some applications, see the <a href="cli.html#uv_threadpool_sizesize"><code>UV_THREADPOOL_SIZE</code></a> 19431cb0ef41Sopenharmony_cidocumentation for more information.</p> 19441cb0ef41Sopenharmony_ci<p>Various networking APIs will call <code>dns.lookup()</code> internally to resolve 19451cb0ef41Sopenharmony_cihost names. If that is an issue, consider resolving the host name to an address 19461cb0ef41Sopenharmony_ciusing <code>dns.resolve()</code> and using the address instead of a host name. Also, some 19471cb0ef41Sopenharmony_cinetworking APIs (such as <a href="net.html#socketconnectoptions-connectlistener"><code>socket.connect()</code></a> and <a href="dgram.html#dgramcreatesocketoptions-callback"><code>dgram.createSocket()</code></a>) 19481cb0ef41Sopenharmony_ciallow the default resolver, <code>dns.lookup()</code>, to be replaced.</p> 19491cb0ef41Sopenharmony_ci<h4><code>dns.resolve()</code>, <code>dns.resolve*()</code>, and <code>dns.reverse()</code><span><a class="mark" href="#dnsresolve-dnsresolve-and-dnsreverse" id="dnsresolve-dnsresolve-and-dnsreverse">#</a></span><a aria-hidden="true" class="legacy" id="dns_dns_resolve_dns_resolve_and_dns_reverse"></a></h4> 19501cb0ef41Sopenharmony_ci<p>These functions are implemented quite differently than <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a>. They 19511cb0ef41Sopenharmony_cido not use <a href="http://man7.org/linux/man-pages/man3/getaddrinfo.3.html"><code>getaddrinfo(3)</code></a> and they <em>always</em> perform a DNS query on the 19521cb0ef41Sopenharmony_cinetwork. This network communication is always done asynchronously and does not 19531cb0ef41Sopenharmony_ciuse libuv's threadpool.</p> 19541cb0ef41Sopenharmony_ci<p>As a result, these functions cannot have the same negative impact on other 19551cb0ef41Sopenharmony_ciprocessing that happens on libuv's threadpool that <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> can have.</p> 19561cb0ef41Sopenharmony_ci<p>They do not use the same set of configuration files that <a href="#dnslookuphostname-options-callback"><code>dns.lookup()</code></a> 19571cb0ef41Sopenharmony_ciuses. For instance, they do not use the configuration from <code>/etc/hosts</code>.</p></section> 19581cb0ef41Sopenharmony_ci <!-- API END --> 19591cb0ef41Sopenharmony_ci </div> 19601cb0ef41Sopenharmony_ci </div> 19611cb0ef41Sopenharmony_ci </div> 19621cb0ef41Sopenharmony_ci</body> 19631cb0ef41Sopenharmony_ci</html> 1964