xref: /kernel/linux/linux-5.10/net/ipv6/Kconfig (revision 8c2ecf20)
18c2ecf20Sopenharmony_ci# SPDX-License-Identifier: GPL-2.0-only
28c2ecf20Sopenharmony_ci#
38c2ecf20Sopenharmony_ci# IPv6 configuration
48c2ecf20Sopenharmony_ci#
58c2ecf20Sopenharmony_ci
68c2ecf20Sopenharmony_ci#   IPv6 as module will cause a CRASH if you try to unload it
78c2ecf20Sopenharmony_cimenuconfig IPV6
88c2ecf20Sopenharmony_ci	tristate "The IPv6 protocol"
98c2ecf20Sopenharmony_ci	default y
108c2ecf20Sopenharmony_ci	help
118c2ecf20Sopenharmony_ci	  Support for IP version 6 (IPv6).
128c2ecf20Sopenharmony_ci
138c2ecf20Sopenharmony_ci	  For general information about IPv6, see
148c2ecf20Sopenharmony_ci	  <https://en.wikipedia.org/wiki/IPv6>.
158c2ecf20Sopenharmony_ci	  For specific information about IPv6 under Linux, see
168c2ecf20Sopenharmony_ci	  Documentation/networking/ipv6.rst and read the HOWTO at
178c2ecf20Sopenharmony_ci	  <https://www.tldp.org/HOWTO/Linux+IPv6-HOWTO/>
188c2ecf20Sopenharmony_ci
198c2ecf20Sopenharmony_ci	  To compile this protocol support as a module, choose M here: the
208c2ecf20Sopenharmony_ci	  module will be called ipv6.
218c2ecf20Sopenharmony_ci
228c2ecf20Sopenharmony_ciif IPV6
238c2ecf20Sopenharmony_ci
248c2ecf20Sopenharmony_ciconfig IPV6_ROUTER_PREF
258c2ecf20Sopenharmony_ci	bool "IPv6: Router Preference (RFC 4191) support"
268c2ecf20Sopenharmony_ci	help
278c2ecf20Sopenharmony_ci	  Router Preference is an optional extension to the Router
288c2ecf20Sopenharmony_ci	  Advertisement message which improves the ability of hosts
298c2ecf20Sopenharmony_ci	  to pick an appropriate router, especially when the hosts
308c2ecf20Sopenharmony_ci	  are placed in a multi-homed network.
318c2ecf20Sopenharmony_ci
328c2ecf20Sopenharmony_ci	  If unsure, say N.
338c2ecf20Sopenharmony_ci
348c2ecf20Sopenharmony_ciconfig IPV6_ROUTE_INFO
358c2ecf20Sopenharmony_ci	bool "IPv6: Route Information (RFC 4191) support"
368c2ecf20Sopenharmony_ci	depends on IPV6_ROUTER_PREF
378c2ecf20Sopenharmony_ci	help
388c2ecf20Sopenharmony_ci	  Support of Route Information.
398c2ecf20Sopenharmony_ci
408c2ecf20Sopenharmony_ci	  If unsure, say N.
418c2ecf20Sopenharmony_ci
428c2ecf20Sopenharmony_ciconfig IPV6_OPTIMISTIC_DAD
438c2ecf20Sopenharmony_ci	bool "IPv6: Enable RFC 4429 Optimistic DAD"
448c2ecf20Sopenharmony_ci	help
458c2ecf20Sopenharmony_ci	  Support for optimistic Duplicate Address Detection. It allows for
468c2ecf20Sopenharmony_ci	  autoconfigured addresses to be used more quickly.
478c2ecf20Sopenharmony_ci
488c2ecf20Sopenharmony_ci	  If unsure, say N.
498c2ecf20Sopenharmony_ci
508c2ecf20Sopenharmony_ciconfig INET6_AH
518c2ecf20Sopenharmony_ci	tristate "IPv6: AH transformation"
528c2ecf20Sopenharmony_ci	select XFRM_AH
538c2ecf20Sopenharmony_ci	help
548c2ecf20Sopenharmony_ci	  Support for IPsec AH (Authentication Header).
558c2ecf20Sopenharmony_ci
568c2ecf20Sopenharmony_ci	  AH can be used with various authentication algorithms.  Besides
578c2ecf20Sopenharmony_ci	  enabling AH support itself, this option enables the generic
588c2ecf20Sopenharmony_ci	  implementations of the algorithms that RFC 8221 lists as MUST be
598c2ecf20Sopenharmony_ci	  implemented.  If you need any other algorithms, you'll need to enable
608c2ecf20Sopenharmony_ci	  them in the crypto API.  You should also enable accelerated
618c2ecf20Sopenharmony_ci	  implementations of any needed algorithms when available.
628c2ecf20Sopenharmony_ci
638c2ecf20Sopenharmony_ci	  If unsure, say Y.
648c2ecf20Sopenharmony_ci
658c2ecf20Sopenharmony_ciconfig INET6_ESP
668c2ecf20Sopenharmony_ci	tristate "IPv6: ESP transformation"
678c2ecf20Sopenharmony_ci	select XFRM_ESP
688c2ecf20Sopenharmony_ci	help
698c2ecf20Sopenharmony_ci	  Support for IPsec ESP (Encapsulating Security Payload).
708c2ecf20Sopenharmony_ci
718c2ecf20Sopenharmony_ci	  ESP can be used with various encryption and authentication algorithms.
728c2ecf20Sopenharmony_ci	  Besides enabling ESP support itself, this option enables the generic
738c2ecf20Sopenharmony_ci	  implementations of the algorithms that RFC 8221 lists as MUST be
748c2ecf20Sopenharmony_ci	  implemented.  If you need any other algorithms, you'll need to enable
758c2ecf20Sopenharmony_ci	  them in the crypto API.  You should also enable accelerated
768c2ecf20Sopenharmony_ci	  implementations of any needed algorithms when available.
778c2ecf20Sopenharmony_ci
788c2ecf20Sopenharmony_ci	  If unsure, say Y.
798c2ecf20Sopenharmony_ci
808c2ecf20Sopenharmony_ciconfig INET6_ESP_OFFLOAD
818c2ecf20Sopenharmony_ci	tristate "IPv6: ESP transformation offload"
828c2ecf20Sopenharmony_ci	depends on INET6_ESP
838c2ecf20Sopenharmony_ci	select XFRM_OFFLOAD
848c2ecf20Sopenharmony_ci	default n
858c2ecf20Sopenharmony_ci	help
868c2ecf20Sopenharmony_ci	  Support for ESP transformation offload. This makes sense
878c2ecf20Sopenharmony_ci	  only if this system really does IPsec and want to do it
888c2ecf20Sopenharmony_ci	  with high throughput. A typical desktop system does not
898c2ecf20Sopenharmony_ci	  need it, even if it does IPsec.
908c2ecf20Sopenharmony_ci
918c2ecf20Sopenharmony_ci	  If unsure, say N.
928c2ecf20Sopenharmony_ci
938c2ecf20Sopenharmony_ciconfig INET6_ESPINTCP
948c2ecf20Sopenharmony_ci	bool "IPv6: ESP in TCP encapsulation (RFC 8229)"
958c2ecf20Sopenharmony_ci	depends on XFRM && INET6_ESP
968c2ecf20Sopenharmony_ci	select STREAM_PARSER
978c2ecf20Sopenharmony_ci	select NET_SOCK_MSG
988c2ecf20Sopenharmony_ci	select XFRM_ESPINTCP
998c2ecf20Sopenharmony_ci	help
1008c2ecf20Sopenharmony_ci	  Support for RFC 8229 encapsulation of ESP and IKE over
1018c2ecf20Sopenharmony_ci	  TCP/IPv6 sockets.
1028c2ecf20Sopenharmony_ci
1038c2ecf20Sopenharmony_ci	  If unsure, say N.
1048c2ecf20Sopenharmony_ci
1058c2ecf20Sopenharmony_ciconfig INET6_IPCOMP
1068c2ecf20Sopenharmony_ci	tristate "IPv6: IPComp transformation"
1078c2ecf20Sopenharmony_ci	select INET6_XFRM_TUNNEL
1088c2ecf20Sopenharmony_ci	select XFRM_IPCOMP
1098c2ecf20Sopenharmony_ci	help
1108c2ecf20Sopenharmony_ci	  Support for IP Payload Compression Protocol (IPComp) (RFC3173),
1118c2ecf20Sopenharmony_ci	  typically needed for IPsec.
1128c2ecf20Sopenharmony_ci
1138c2ecf20Sopenharmony_ci	  If unsure, say Y.
1148c2ecf20Sopenharmony_ci
1158c2ecf20Sopenharmony_ciconfig IPV6_MIP6
1168c2ecf20Sopenharmony_ci	tristate "IPv6: Mobility"
1178c2ecf20Sopenharmony_ci	select XFRM
1188c2ecf20Sopenharmony_ci	help
1198c2ecf20Sopenharmony_ci	  Support for IPv6 Mobility described in RFC 3775.
1208c2ecf20Sopenharmony_ci
1218c2ecf20Sopenharmony_ci	  If unsure, say N.
1228c2ecf20Sopenharmony_ci
1238c2ecf20Sopenharmony_ciconfig IPV6_ILA
1248c2ecf20Sopenharmony_ci	tristate "IPv6: Identifier Locator Addressing (ILA)"
1258c2ecf20Sopenharmony_ci	depends on NETFILTER
1268c2ecf20Sopenharmony_ci	select DST_CACHE
1278c2ecf20Sopenharmony_ci	select LWTUNNEL
1288c2ecf20Sopenharmony_ci	help
1298c2ecf20Sopenharmony_ci	  Support for IPv6 Identifier Locator Addressing (ILA).
1308c2ecf20Sopenharmony_ci
1318c2ecf20Sopenharmony_ci	  ILA is a mechanism to do network virtualization without
1328c2ecf20Sopenharmony_ci	  encapsulation. The basic concept of ILA is that we split an
1338c2ecf20Sopenharmony_ci	  IPv6 address into a 64 bit locator and 64 bit identifier. The
1348c2ecf20Sopenharmony_ci	  identifier is the identity of an entity in communication
1358c2ecf20Sopenharmony_ci	  ("who") and the locator expresses the location of the
1368c2ecf20Sopenharmony_ci	  entity ("where").
1378c2ecf20Sopenharmony_ci
1388c2ecf20Sopenharmony_ci	  ILA can be configured using the "encap ila" option with
1398c2ecf20Sopenharmony_ci	  "ip -6 route" command. ILA is described in
1408c2ecf20Sopenharmony_ci	  https://tools.ietf.org/html/draft-herbert-nvo3-ila-00.
1418c2ecf20Sopenharmony_ci
1428c2ecf20Sopenharmony_ci	  If unsure, say N.
1438c2ecf20Sopenharmony_ci
1448c2ecf20Sopenharmony_ciconfig INET6_XFRM_TUNNEL
1458c2ecf20Sopenharmony_ci	tristate
1468c2ecf20Sopenharmony_ci	select INET6_TUNNEL
1478c2ecf20Sopenharmony_ci	default n
1488c2ecf20Sopenharmony_ci
1498c2ecf20Sopenharmony_ciconfig INET6_TUNNEL
1508c2ecf20Sopenharmony_ci	tristate
1518c2ecf20Sopenharmony_ci	default n
1528c2ecf20Sopenharmony_ci
1538c2ecf20Sopenharmony_ciconfig IPV6_VTI
1548c2ecf20Sopenharmony_citristate "Virtual (secure) IPv6: tunneling"
1558c2ecf20Sopenharmony_ci	select IPV6_TUNNEL
1568c2ecf20Sopenharmony_ci	select NET_IP_TUNNEL
1578c2ecf20Sopenharmony_ci	select XFRM
1588c2ecf20Sopenharmony_ci	help
1598c2ecf20Sopenharmony_ci	Tunneling means encapsulating data of one protocol type within
1608c2ecf20Sopenharmony_ci	another protocol and sending it over a channel that understands the
1618c2ecf20Sopenharmony_ci	encapsulating protocol. This can be used with xfrm mode tunnel to give
1628c2ecf20Sopenharmony_ci	the notion of a secure tunnel for IPSEC and then use routing protocol
1638c2ecf20Sopenharmony_ci	on top.
1648c2ecf20Sopenharmony_ci
1658c2ecf20Sopenharmony_ciconfig IPV6_SIT
1668c2ecf20Sopenharmony_ci	tristate "IPv6: IPv6-in-IPv4 tunnel (SIT driver)"
1678c2ecf20Sopenharmony_ci	select INET_TUNNEL
1688c2ecf20Sopenharmony_ci	select NET_IP_TUNNEL
1698c2ecf20Sopenharmony_ci	select IPV6_NDISC_NODETYPE
1708c2ecf20Sopenharmony_ci	default y
1718c2ecf20Sopenharmony_ci	help
1728c2ecf20Sopenharmony_ci	  Tunneling means encapsulating data of one protocol type within
1738c2ecf20Sopenharmony_ci	  another protocol and sending it over a channel that understands the
1748c2ecf20Sopenharmony_ci	  encapsulating protocol. This driver implements encapsulation of IPv6
1758c2ecf20Sopenharmony_ci	  into IPv4 packets. This is useful if you want to connect two IPv6
1768c2ecf20Sopenharmony_ci	  networks over an IPv4-only path.
1778c2ecf20Sopenharmony_ci
1788c2ecf20Sopenharmony_ci	  Saying M here will produce a module called sit. If unsure, say Y.
1798c2ecf20Sopenharmony_ci
1808c2ecf20Sopenharmony_ciconfig IPV6_SIT_6RD
1818c2ecf20Sopenharmony_ci	bool "IPv6: IPv6 Rapid Deployment (6RD)"
1828c2ecf20Sopenharmony_ci	depends on IPV6_SIT
1838c2ecf20Sopenharmony_ci	default n
1848c2ecf20Sopenharmony_ci	help
1858c2ecf20Sopenharmony_ci	  IPv6 Rapid Deployment (6rd; draft-ietf-softwire-ipv6-6rd) builds upon
1868c2ecf20Sopenharmony_ci	  mechanisms of 6to4 (RFC3056) to enable a service provider to rapidly
1878c2ecf20Sopenharmony_ci	  deploy IPv6 unicast service to IPv4 sites to which it provides
1888c2ecf20Sopenharmony_ci	  customer premise equipment.  Like 6to4, it utilizes stateless IPv6 in
1898c2ecf20Sopenharmony_ci	  IPv4 encapsulation in order to transit IPv4-only network
1908c2ecf20Sopenharmony_ci	  infrastructure.  Unlike 6to4, a 6rd service provider uses an IPv6
1918c2ecf20Sopenharmony_ci	  prefix of its own in place of the fixed 6to4 prefix.
1928c2ecf20Sopenharmony_ci
1938c2ecf20Sopenharmony_ci	  With this option enabled, the SIT driver offers 6rd functionality by
1948c2ecf20Sopenharmony_ci	  providing additional ioctl API to configure the IPv6 Prefix for in
1958c2ecf20Sopenharmony_ci	  stead of static 2002::/16 for 6to4.
1968c2ecf20Sopenharmony_ci
1978c2ecf20Sopenharmony_ci	  If unsure, say N.
1988c2ecf20Sopenharmony_ci
1998c2ecf20Sopenharmony_ciconfig IPV6_NDISC_NODETYPE
2008c2ecf20Sopenharmony_ci	bool
2018c2ecf20Sopenharmony_ci
2028c2ecf20Sopenharmony_ciconfig IPV6_TUNNEL
2038c2ecf20Sopenharmony_ci	tristate "IPv6: IP-in-IPv6 tunnel (RFC2473)"
2048c2ecf20Sopenharmony_ci	select INET6_TUNNEL
2058c2ecf20Sopenharmony_ci	select DST_CACHE
2068c2ecf20Sopenharmony_ci	select GRO_CELLS
2078c2ecf20Sopenharmony_ci	help
2088c2ecf20Sopenharmony_ci	  Support for IPv6-in-IPv6 and IPv4-in-IPv6 tunnels described in
2098c2ecf20Sopenharmony_ci	  RFC 2473.
2108c2ecf20Sopenharmony_ci
2118c2ecf20Sopenharmony_ci	  If unsure, say N.
2128c2ecf20Sopenharmony_ci
2138c2ecf20Sopenharmony_ciconfig IPV6_GRE
2148c2ecf20Sopenharmony_ci	tristate "IPv6: GRE tunnel"
2158c2ecf20Sopenharmony_ci	select IPV6_TUNNEL
2168c2ecf20Sopenharmony_ci	select NET_IP_TUNNEL
2178c2ecf20Sopenharmony_ci	depends on NET_IPGRE_DEMUX
2188c2ecf20Sopenharmony_ci	help
2198c2ecf20Sopenharmony_ci	  Tunneling means encapsulating data of one protocol type within
2208c2ecf20Sopenharmony_ci	  another protocol and sending it over a channel that understands the
2218c2ecf20Sopenharmony_ci	  encapsulating protocol. This particular tunneling driver implements
2228c2ecf20Sopenharmony_ci	  GRE (Generic Routing Encapsulation) and at this time allows
2238c2ecf20Sopenharmony_ci	  encapsulating of IPv4 or IPv6 over existing IPv6 infrastructure.
2248c2ecf20Sopenharmony_ci	  This driver is useful if the other endpoint is a Cisco router: Cisco
2258c2ecf20Sopenharmony_ci	  likes GRE much better than the other Linux tunneling driver ("IP
2268c2ecf20Sopenharmony_ci	  tunneling" above). In addition, GRE allows multicast redistribution
2278c2ecf20Sopenharmony_ci	  through the tunnel.
2288c2ecf20Sopenharmony_ci
2298c2ecf20Sopenharmony_ci	  Saying M here will produce a module called ip6_gre. If unsure, say N.
2308c2ecf20Sopenharmony_ci
2318c2ecf20Sopenharmony_ciconfig IPV6_FOU
2328c2ecf20Sopenharmony_ci	tristate
2338c2ecf20Sopenharmony_ci	default NET_FOU && IPV6
2348c2ecf20Sopenharmony_ci
2358c2ecf20Sopenharmony_ciconfig IPV6_FOU_TUNNEL
2368c2ecf20Sopenharmony_ci	tristate
2378c2ecf20Sopenharmony_ci	default NET_FOU_IP_TUNNELS && IPV6_FOU
2388c2ecf20Sopenharmony_ci	select IPV6_TUNNEL
2398c2ecf20Sopenharmony_ci
2408c2ecf20Sopenharmony_ciconfig IPV6_MULTIPLE_TABLES
2418c2ecf20Sopenharmony_ci	bool "IPv6: Multiple Routing Tables"
2428c2ecf20Sopenharmony_ci	select FIB_RULES
2438c2ecf20Sopenharmony_ci	help
2448c2ecf20Sopenharmony_ci	  Support multiple routing tables.
2458c2ecf20Sopenharmony_ci
2468c2ecf20Sopenharmony_ciconfig IPV6_SUBTREES
2478c2ecf20Sopenharmony_ci	bool "IPv6: source address based routing"
2488c2ecf20Sopenharmony_ci	depends on IPV6_MULTIPLE_TABLES
2498c2ecf20Sopenharmony_ci	help
2508c2ecf20Sopenharmony_ci	  Enable routing by source address or prefix.
2518c2ecf20Sopenharmony_ci
2528c2ecf20Sopenharmony_ci	  The destination address is still the primary routing key, so mixing
2538c2ecf20Sopenharmony_ci	  normal and source prefix specific routes in the same routing table
2548c2ecf20Sopenharmony_ci	  may sometimes lead to unintended routing behavior.  This can be
2558c2ecf20Sopenharmony_ci	  avoided by defining different routing tables for the normal and
2568c2ecf20Sopenharmony_ci	  source prefix specific routes.
2578c2ecf20Sopenharmony_ci
2588c2ecf20Sopenharmony_ci	  If unsure, say N.
2598c2ecf20Sopenharmony_ci
2608c2ecf20Sopenharmony_ciconfig IPV6_MROUTE
2618c2ecf20Sopenharmony_ci	bool "IPv6: multicast routing"
2628c2ecf20Sopenharmony_ci	depends on IPV6
2638c2ecf20Sopenharmony_ci	select IP_MROUTE_COMMON
2648c2ecf20Sopenharmony_ci	help
2658c2ecf20Sopenharmony_ci	  Support for IPv6 multicast forwarding.
2668c2ecf20Sopenharmony_ci	  If unsure, say N.
2678c2ecf20Sopenharmony_ci
2688c2ecf20Sopenharmony_ciconfig IPV6_MROUTE_MULTIPLE_TABLES
2698c2ecf20Sopenharmony_ci	bool "IPv6: multicast policy routing"
2708c2ecf20Sopenharmony_ci	depends on IPV6_MROUTE
2718c2ecf20Sopenharmony_ci	select FIB_RULES
2728c2ecf20Sopenharmony_ci	help
2738c2ecf20Sopenharmony_ci	  Normally, a multicast router runs a userspace daemon and decides
2748c2ecf20Sopenharmony_ci	  what to do with a multicast packet based on the source and
2758c2ecf20Sopenharmony_ci	  destination addresses. If you say Y here, the multicast router
2768c2ecf20Sopenharmony_ci	  will also be able to take interfaces and packet marks into
2778c2ecf20Sopenharmony_ci	  account and run multiple instances of userspace daemons
2788c2ecf20Sopenharmony_ci	  simultaneously, each one handling a single table.
2798c2ecf20Sopenharmony_ci
2808c2ecf20Sopenharmony_ci	  If unsure, say N.
2818c2ecf20Sopenharmony_ci
2828c2ecf20Sopenharmony_ciconfig IPV6_PIMSM_V2
2838c2ecf20Sopenharmony_ci	bool "IPv6: PIM-SM version 2 support"
2848c2ecf20Sopenharmony_ci	depends on IPV6_MROUTE
2858c2ecf20Sopenharmony_ci	help
2868c2ecf20Sopenharmony_ci	  Support for IPv6 PIM multicast routing protocol PIM-SMv2.
2878c2ecf20Sopenharmony_ci	  If unsure, say N.
2888c2ecf20Sopenharmony_ci
2898c2ecf20Sopenharmony_ciconfig IPV6_SEG6_LWTUNNEL
2908c2ecf20Sopenharmony_ci	bool "IPv6: Segment Routing Header encapsulation support"
2918c2ecf20Sopenharmony_ci	depends on IPV6
2928c2ecf20Sopenharmony_ci	select LWTUNNEL
2938c2ecf20Sopenharmony_ci	select DST_CACHE
2948c2ecf20Sopenharmony_ci	select IPV6_MULTIPLE_TABLES
2958c2ecf20Sopenharmony_ci	help
2968c2ecf20Sopenharmony_ci	  Support for encapsulation of packets within an outer IPv6
2978c2ecf20Sopenharmony_ci	  header and a Segment Routing Header using the lightweight
2988c2ecf20Sopenharmony_ci	  tunnels mechanism. Also enable support for advanced local
2998c2ecf20Sopenharmony_ci	  processing of SRv6 packets based on their active segment.
3008c2ecf20Sopenharmony_ci
3018c2ecf20Sopenharmony_ci	  If unsure, say N.
3028c2ecf20Sopenharmony_ci
3038c2ecf20Sopenharmony_ciconfig IPV6_SEG6_HMAC
3048c2ecf20Sopenharmony_ci	bool "IPv6: Segment Routing HMAC support"
3058c2ecf20Sopenharmony_ci	depends on IPV6
3068c2ecf20Sopenharmony_ci	select CRYPTO
3078c2ecf20Sopenharmony_ci	select CRYPTO_HMAC
3088c2ecf20Sopenharmony_ci	select CRYPTO_SHA1
3098c2ecf20Sopenharmony_ci	select CRYPTO_SHA256
3108c2ecf20Sopenharmony_ci	help
3118c2ecf20Sopenharmony_ci	  Support for HMAC signature generation and verification
3128c2ecf20Sopenharmony_ci	  of SR-enabled packets.
3138c2ecf20Sopenharmony_ci
3148c2ecf20Sopenharmony_ci	  If unsure, say N.
3158c2ecf20Sopenharmony_ci
3168c2ecf20Sopenharmony_ciconfig IPV6_SEG6_BPF
3178c2ecf20Sopenharmony_ci	def_bool y
3188c2ecf20Sopenharmony_ci	depends on IPV6_SEG6_LWTUNNEL
3198c2ecf20Sopenharmony_ci	depends on IPV6 = y
3208c2ecf20Sopenharmony_ci
3218c2ecf20Sopenharmony_ciconfig IPV6_RPL_LWTUNNEL
3228c2ecf20Sopenharmony_ci	bool "IPv6: RPL Source Routing Header support"
3238c2ecf20Sopenharmony_ci	depends on IPV6
3248c2ecf20Sopenharmony_ci	select LWTUNNEL
3258c2ecf20Sopenharmony_ci	help
3268c2ecf20Sopenharmony_ci	  Support for RFC6554 RPL Source Routing Header using the lightweight
3278c2ecf20Sopenharmony_ci	  tunnels mechanism.
3288c2ecf20Sopenharmony_ci
3298c2ecf20Sopenharmony_ci	  If unsure, say N.
3308c2ecf20Sopenharmony_ci
3318c2ecf20Sopenharmony_ciendif # IPV6
332