xref: /openbmc/linux/net/ipv6/Kconfig (revision b35c9683)
1ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only
21da177e4SLinus Torvalds#
31da177e4SLinus Torvalds# IPv6 configuration
41da177e4SLinus Torvalds#
56a2e9b73SSam Ravnborg
66a2e9b73SSam Ravnborg#   IPv6 as module will cause a CRASH if you try to unload it
70b18542bSJan Engelhardtmenuconfig IPV6
86a2e9b73SSam Ravnborg	tristate "The IPv6 protocol"
9de551f2eSTom Herbert	default y
10*ec8f7f48SEric Biggers	select CRYPTO_LIB_SHA1
11a7f7f624SMasahiro Yamada	help
12de551f2eSTom Herbert	  Support for IP version 6 (IPv6).
136a2e9b73SSam Ravnborg
146a2e9b73SSam Ravnborg	  For general information about IPv6, see
15242260fbSChristian Kujau	  <https://en.wikipedia.org/wiki/IPv6>.
16de551f2eSTom Herbert	  For specific information about IPv6 under Linux, see
1719093313SMauro Carvalho Chehab	  Documentation/networking/ipv6.rst and read the HOWTO at
187a6498ebSAlexander A. Klimov	  <https://www.tldp.org/HOWTO/Linux+IPv6-HOWTO/>
196a2e9b73SSam Ravnborg
206a2e9b73SSam Ravnborg	  To compile this protocol support as a module, choose M here: the
216a2e9b73SSam Ravnborg	  module will be called ipv6.
226a2e9b73SSam Ravnborg
230b18542bSJan Engelhardtif IPV6
240b18542bSJan Engelhardt
25ebacaaa0SYOSHIFUJI Hideakiconfig IPV6_ROUTER_PREF
26ebacaaa0SYOSHIFUJI Hideaki	bool "IPv6: Router Preference (RFC 4191) support"
27a7f7f624SMasahiro Yamada	help
28ebacaaa0SYOSHIFUJI Hideaki	  Router Preference is an optional extension to the Router
29692105b8SMatt LaPlante	  Advertisement message which improves the ability of hosts
30692105b8SMatt LaPlante	  to pick an appropriate router, especially when the hosts
31692105b8SMatt LaPlante	  are placed in a multi-homed network.
32ebacaaa0SYOSHIFUJI Hideaki
33ebacaaa0SYOSHIFUJI Hideaki	  If unsure, say N.
34ebacaaa0SYOSHIFUJI Hideaki
3570ceb4f5SYOSHIFUJI Hideakiconfig IPV6_ROUTE_INFO
36f9ceb16eSKees Cook	bool "IPv6: Route Information (RFC 4191) support"
37f9ceb16eSKees Cook	depends on IPV6_ROUTER_PREF
38a7f7f624SMasahiro Yamada	help
39a9f71d0dSGeorg Hofmann	  Support of Route Information.
4070ceb4f5SYOSHIFUJI Hideaki
4170ceb4f5SYOSHIFUJI Hideaki	  If unsure, say N.
4270ceb4f5SYOSHIFUJI Hideaki
4395c385b4SNeil Hormanconfig IPV6_OPTIMISTIC_DAD
44f9ceb16eSKees Cook	bool "IPv6: Enable RFC 4429 Optimistic DAD"
45a7f7f624SMasahiro Yamada	help
46a9f71d0dSGeorg Hofmann	  Support for optimistic Duplicate Address Detection. It allows for
47a9f71d0dSGeorg Hofmann	  autoconfigured addresses to be used more quickly.
4895c385b4SNeil Horman
4995c385b4SNeil Horman	  If unsure, say N.
5095c385b4SNeil Horman
511da177e4SLinus Torvaldsconfig INET6_AH
521da177e4SLinus Torvalds	tristate "IPv6: AH transformation"
537d4e3919SEric Biggers	select XFRM_AH
54a7f7f624SMasahiro Yamada	help
55be013698SEric Biggers	  Support for IPsec AH (Authentication Header).
56be013698SEric Biggers
57be013698SEric Biggers	  AH can be used with various authentication algorithms.  Besides
58be013698SEric Biggers	  enabling AH support itself, this option enables the generic
59be013698SEric Biggers	  implementations of the algorithms that RFC 8221 lists as MUST be
60be013698SEric Biggers	  implemented.  If you need any other algorithms, you'll need to enable
61be013698SEric Biggers	  them in the crypto API.  You should also enable accelerated
62be013698SEric Biggers	  implementations of any needed algorithms when available.
631da177e4SLinus Torvalds
641da177e4SLinus Torvalds	  If unsure, say Y.
651da177e4SLinus Torvalds
661da177e4SLinus Torvaldsconfig INET6_ESP
671da177e4SLinus Torvalds	tristate "IPv6: ESP transformation"
687d4e3919SEric Biggers	select XFRM_ESP
69a7f7f624SMasahiro Yamada	help
70be013698SEric Biggers	  Support for IPsec ESP (Encapsulating Security Payload).
71be013698SEric Biggers
72be013698SEric Biggers	  ESP can be used with various encryption and authentication algorithms.
73be013698SEric Biggers	  Besides enabling ESP support itself, this option enables the generic
74be013698SEric Biggers	  implementations of the algorithms that RFC 8221 lists as MUST be
75be013698SEric Biggers	  implemented.  If you need any other algorithms, you'll need to enable
76be013698SEric Biggers	  them in the crypto API.  You should also enable accelerated
77be013698SEric Biggers	  implementations of any needed algorithms when available.
781da177e4SLinus Torvalds
791da177e4SLinus Torvalds	  If unsure, say Y.
801da177e4SLinus Torvalds
817785bba2SSteffen Klassertconfig INET6_ESP_OFFLOAD
827785bba2SSteffen Klassert	tristate "IPv6: ESP transformation offload"
837785bba2SSteffen Klassert	depends on INET6_ESP
847785bba2SSteffen Klassert	select XFRM_OFFLOAD
857785bba2SSteffen Klassert	default n
86a7f7f624SMasahiro Yamada	help
877785bba2SSteffen Klassert	  Support for ESP transformation offload. This makes sense
887785bba2SSteffen Klassert	  only if this system really does IPsec and want to do it
897785bba2SSteffen Klassert	  with high throughput. A typical desktop system does not
907785bba2SSteffen Klassert	  need it, even if it does IPsec.
917785bba2SSteffen Klassert
927785bba2SSteffen Klassert	  If unsure, say N.
937785bba2SSteffen Klassert
9426333c37SSabrina Dubrocaconfig INET6_ESPINTCP
9526333c37SSabrina Dubroca	bool "IPv6: ESP in TCP encapsulation (RFC 8229)"
9626333c37SSabrina Dubroca	depends on XFRM && INET6_ESP
9726333c37SSabrina Dubroca	select STREAM_PARSER
9826333c37SSabrina Dubroca	select NET_SOCK_MSG
9926333c37SSabrina Dubroca	select XFRM_ESPINTCP
10026333c37SSabrina Dubroca	help
10126333c37SSabrina Dubroca	  Support for RFC 8229 encapsulation of ESP and IKE over
10226333c37SSabrina Dubroca	  TCP/IPv6 sockets.
10326333c37SSabrina Dubroca
10426333c37SSabrina Dubroca	  If unsure, say N.
10526333c37SSabrina Dubroca
1061da177e4SLinus Torvaldsconfig INET6_IPCOMP
1071da177e4SLinus Torvalds	tristate "IPv6: IPComp transformation"
108d2acc347SHerbert Xu	select INET6_XFRM_TUNNEL
1096fccab67SHerbert Xu	select XFRM_IPCOMP
110a7f7f624SMasahiro Yamada	help
1111da177e4SLinus Torvalds	  Support for IP Payload Compression Protocol (IPComp) (RFC3173),
1121da177e4SLinus Torvalds	  typically needed for IPsec.
1131da177e4SLinus Torvalds
1141da177e4SLinus Torvalds	  If unsure, say Y.
1151da177e4SLinus Torvalds
116ee538268SMasahide NAKAMURAconfig IPV6_MIP6
117f9ceb16eSKees Cook	tristate "IPv6: Mobility"
118ee538268SMasahide NAKAMURA	select XFRM
119a7f7f624SMasahiro Yamada	help
120ee538268SMasahide NAKAMURA	  Support for IPv6 Mobility described in RFC 3775.
121ee538268SMasahide NAKAMURA
122ee538268SMasahide NAKAMURA	  If unsure, say N.
123ee538268SMasahide NAKAMURA
12465d7ab8dSTom Herbertconfig IPV6_ILA
12565d7ab8dSTom Herbert	tristate "IPv6: Identifier Locator Addressing (ILA)"
1268cb964daSArnd Bergmann	depends on NETFILTER
12783ed7d1fSArnd Bergmann	select DST_CACHE
12865d7ab8dSTom Herbert	select LWTUNNEL
129a7f7f624SMasahiro Yamada	help
13065d7ab8dSTom Herbert	  Support for IPv6 Identifier Locator Addressing (ILA).
13165d7ab8dSTom Herbert
13265d7ab8dSTom Herbert	  ILA is a mechanism to do network virtualization without
13365d7ab8dSTom Herbert	  encapsulation. The basic concept of ILA is that we split an
13465d7ab8dSTom Herbert	  IPv6 address into a 64 bit locator and 64 bit identifier. The
13565d7ab8dSTom Herbert	  identifier is the identity of an entity in communication
13665d7ab8dSTom Herbert	  ("who") and the locator expresses the location of the
13765d7ab8dSTom Herbert	  entity ("where").
13865d7ab8dSTom Herbert
13965d7ab8dSTom Herbert	  ILA can be configured using the "encap ila" option with
14065d7ab8dSTom Herbert	  "ip -6 route" command. ILA is described in
14165d7ab8dSTom Herbert	  https://tools.ietf.org/html/draft-herbert-nvo3-ila-00.
14265d7ab8dSTom Herbert
14365d7ab8dSTom Herbert	  If unsure, say N.
14465d7ab8dSTom Herbert
145d2acc347SHerbert Xuconfig INET6_XFRM_TUNNEL
146d2acc347SHerbert Xu	tristate
147d2acc347SHerbert Xu	select INET6_TUNNEL
148d2acc347SHerbert Xu	default n
1491da177e4SLinus Torvalds
150d2acc347SHerbert Xuconfig INET6_TUNNEL
151d2acc347SHerbert Xu	tristate
152d2acc347SHerbert Xu	default n
1531da177e4SLinus Torvalds
154ed1efb2aSSteffen Klassertconfig IPV6_VTI
155ed1efb2aSSteffen Klassert	tristate "Virtual (secure) IPv6: tunneling"
156ed1efb2aSSteffen Klassert	select IPV6_TUNNEL
157876fc03aSSteffen Klassert	select NET_IP_TUNNEL
1584c145dceSFlorian Westphal	select XFRM
159a7f7f624SMasahiro Yamada	help
160ed1efb2aSSteffen Klassert	Tunneling means encapsulating data of one protocol type within
161ed1efb2aSSteffen Klassert	another protocol and sending it over a channel that understands the
162ed1efb2aSSteffen Klassert	encapsulating protocol. This can be used with xfrm mode tunnel to give
163ed1efb2aSSteffen Klassert	the notion of a secure tunnel for IPSEC and then use routing protocol
164ed1efb2aSSteffen Klassert	on top.
165ed1efb2aSSteffen Klassert
166989e5b96SJoerg Roedelconfig IPV6_SIT
167989e5b96SJoerg Roedel	tristate "IPv6: IPv6-in-IPv4 tunnel (SIT driver)"
168c73cb5a2SKazunori MIYAZAWA	select INET_TUNNEL
169f61dd388SPravin B Shelar	select NET_IP_TUNNEL
170de357cc0SYOSHIFUJI Hideaki	select IPV6_NDISC_NODETYPE
171989e5b96SJoerg Roedel	default y
172a7f7f624SMasahiro Yamada	help
173989e5b96SJoerg Roedel	  Tunneling means encapsulating data of one protocol type within
174989e5b96SJoerg Roedel	  another protocol and sending it over a channel that understands the
175989e5b96SJoerg Roedel	  encapsulating protocol. This driver implements encapsulation of IPv6
1765c5d6dabSDavid S. Miller	  into IPv4 packets. This is useful if you want to connect two IPv6
177989e5b96SJoerg Roedel	  networks over an IPv4-only path.
178989e5b96SJoerg Roedel
1794737f097SPavel Machek	  Saying M here will produce a module called sit. If unsure, say Y.
180989e5b96SJoerg Roedel
181fa857afcSYOSHIFUJI Hideaki / 吉藤英明config IPV6_SIT_6RD
182f9ceb16eSKees Cook	bool "IPv6: IPv6 Rapid Deployment (6RD)"
183f9ceb16eSKees Cook	depends on IPV6_SIT
184fa857afcSYOSHIFUJI Hideaki / 吉藤英明	default n
185a7f7f624SMasahiro Yamada	help
186fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  IPv6 Rapid Deployment (6rd; draft-ietf-softwire-ipv6-6rd) builds upon
187fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  mechanisms of 6to4 (RFC3056) to enable a service provider to rapidly
188fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  deploy IPv6 unicast service to IPv4 sites to which it provides
189fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  customer premise equipment.  Like 6to4, it utilizes stateless IPv6 in
190fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  IPv4 encapsulation in order to transit IPv4-only network
191fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  infrastructure.  Unlike 6to4, a 6rd service provider uses an IPv6
192fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  prefix of its own in place of the fixed 6to4 prefix.
193fa857afcSYOSHIFUJI Hideaki / 吉藤英明
194fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  With this option enabled, the SIT driver offers 6rd functionality by
195fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  providing additional ioctl API to configure the IPv6 Prefix for in
196fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  stead of static 2002::/16 for 6to4.
197fa857afcSYOSHIFUJI Hideaki / 吉藤英明
198fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  If unsure, say N.
199fa857afcSYOSHIFUJI Hideaki / 吉藤英明
200de357cc0SYOSHIFUJI Hideakiconfig IPV6_NDISC_NODETYPE
201de357cc0SYOSHIFUJI Hideaki	bool
202de357cc0SYOSHIFUJI Hideaki
2031da177e4SLinus Torvaldsconfig IPV6_TUNNEL
20438fe999eSYOSHIFUJI Hideaki	tristate "IPv6: IP-in-IPv6 tunnel (RFC2473)"
205d2acc347SHerbert Xu	select INET6_TUNNEL
206607f725fSPaolo Abeni	select DST_CACHE
20797e219b7SEric Dumazet	select GRO_CELLS
208a7f7f624SMasahiro Yamada	help
20938fe999eSYOSHIFUJI Hideaki	  Support for IPv6-in-IPv6 and IPv4-in-IPv6 tunnels described in
21038fe999eSYOSHIFUJI Hideaki	  RFC 2473.
2111da177e4SLinus Torvalds
2121da177e4SLinus Torvalds	  If unsure, say N.
2131da177e4SLinus Torvalds
214c12b395aSxeb@mail.ruconfig IPV6_GRE
215c12b395aSxeb@mail.ru	tristate "IPv6: GRE tunnel"
216c12b395aSxeb@mail.ru	select IPV6_TUNNEL
217f61dd388SPravin B Shelar	select NET_IP_TUNNEL
2188bf42e9eSArnd Bergmann	depends on NET_IPGRE_DEMUX
219a7f7f624SMasahiro Yamada	help
220c12b395aSxeb@mail.ru	  Tunneling means encapsulating data of one protocol type within
221c12b395aSxeb@mail.ru	  another protocol and sending it over a channel that understands the
222c12b395aSxeb@mail.ru	  encapsulating protocol. This particular tunneling driver implements
223c12b395aSxeb@mail.ru	  GRE (Generic Routing Encapsulation) and at this time allows
224c12b395aSxeb@mail.ru	  encapsulating of IPv4 or IPv6 over existing IPv6 infrastructure.
225c12b395aSxeb@mail.ru	  This driver is useful if the other endpoint is a Cisco router: Cisco
226c12b395aSxeb@mail.ru	  likes GRE much better than the other Linux tunneling driver ("IP
227c12b395aSxeb@mail.ru	  tunneling" above). In addition, GRE allows multicast redistribution
228c12b395aSxeb@mail.ru	  through the tunnel.
229c12b395aSxeb@mail.ru
230c12b395aSxeb@mail.ru	  Saying M here will produce a module called ip6_gre. If unsure, say N.
231c12b395aSxeb@mail.ru
232fabb13dbSArnd Bergmannconfig IPV6_FOU
233fabb13dbSArnd Bergmann	tristate
234fabb13dbSArnd Bergmann	default NET_FOU && IPV6
235fabb13dbSArnd Bergmann
236fabb13dbSArnd Bergmannconfig IPV6_FOU_TUNNEL
237fabb13dbSArnd Bergmann	tristate
238fabb13dbSArnd Bergmann	default NET_FOU_IP_TUNNELS && IPV6_FOU
23995e4daa8SArnd Bergmann	select IPV6_TUNNEL
240fabb13dbSArnd Bergmann
241264e91b6SVille Nuorvalaconfig IPV6_MULTIPLE_TABLES
242264e91b6SVille Nuorvala	bool "IPv6: Multiple Routing Tables"
243264e91b6SVille Nuorvala	select FIB_RULES
244a7f7f624SMasahiro Yamada	help
245264e91b6SVille Nuorvala	  Support multiple routing tables.
246264e91b6SVille Nuorvala
2474e96c2b4SYOSHIFUJI Hideakiconfig IPV6_SUBTREES
2484e96c2b4SYOSHIFUJI Hideaki	bool "IPv6: source address based routing"
249264e91b6SVille Nuorvala	depends on IPV6_MULTIPLE_TABLES
250a7f7f624SMasahiro Yamada	help
2514e96c2b4SYOSHIFUJI Hideaki	  Enable routing by source address or prefix.
2524e96c2b4SYOSHIFUJI Hideaki
2534e96c2b4SYOSHIFUJI Hideaki	  The destination address is still the primary routing key, so mixing
2544e96c2b4SYOSHIFUJI Hideaki	  normal and source prefix specific routes in the same routing table
2554e96c2b4SYOSHIFUJI Hideaki	  may sometimes lead to unintended routing behavior.  This can be
2564e96c2b4SYOSHIFUJI Hideaki	  avoided by defining different routing tables for the normal and
2574e96c2b4SYOSHIFUJI Hideaki	  source prefix specific routes.
2584e96c2b4SYOSHIFUJI Hideaki
2594e96c2b4SYOSHIFUJI Hideaki	  If unsure, say N.
2604e96c2b4SYOSHIFUJI Hideaki
2617bc570c8SYOSHIFUJI Hideakiconfig IPV6_MROUTE
262f9ceb16eSKees Cook	bool "IPv6: multicast routing"
263f9ceb16eSKees Cook	depends on IPV6
2646853f21fSYuval Mintz	select IP_MROUTE_COMMON
265a7f7f624SMasahiro Yamada	help
266a9f71d0dSGeorg Hofmann	  Support for IPv6 multicast forwarding.
2677bc570c8SYOSHIFUJI Hideaki	  If unsure, say N.
2687bc570c8SYOSHIFUJI Hideaki
269d1db275dSPatrick McHardyconfig IPV6_MROUTE_MULTIPLE_TABLES
270d1db275dSPatrick McHardy	bool "IPv6: multicast policy routing"
271d1db275dSPatrick McHardy	depends on IPV6_MROUTE
272d1db275dSPatrick McHardy	select FIB_RULES
273d1db275dSPatrick McHardy	help
274d1db275dSPatrick McHardy	  Normally, a multicast router runs a userspace daemon and decides
275d1db275dSPatrick McHardy	  what to do with a multicast packet based on the source and
276d1db275dSPatrick McHardy	  destination addresses. If you say Y here, the multicast router
277d1db275dSPatrick McHardy	  will also be able to take interfaces and packet marks into
278d1db275dSPatrick McHardy	  account and run multiple instances of userspace daemons
279d1db275dSPatrick McHardy	  simultaneously, each one handling a single table.
280d1db275dSPatrick McHardy
281d1db275dSPatrick McHardy	  If unsure, say N.
282d1db275dSPatrick McHardy
28314fb64e1SYOSHIFUJI Hideakiconfig IPV6_PIMSM_V2
284f9ceb16eSKees Cook	bool "IPv6: PIM-SM version 2 support"
28514fb64e1SYOSHIFUJI Hideaki	depends on IPV6_MROUTE
286a7f7f624SMasahiro Yamada	help
28714fb64e1SYOSHIFUJI Hideaki	  Support for IPv6 PIM multicast routing protocol PIM-SMv2.
28814fb64e1SYOSHIFUJI Hideaki	  If unsure, say N.
28914fb64e1SYOSHIFUJI Hideaki
29046738b13SDavid Lebrunconfig IPV6_SEG6_LWTUNNEL
29146738b13SDavid Lebrun	bool "IPv6: Segment Routing Header encapsulation support"
29246738b13SDavid Lebrun	depends on IPV6
29346738b13SDavid Lebrun	select LWTUNNEL
294402a5bc4SDavid Lebrun	select DST_CACHE
295d7a669ddSDavid Lebrun	select IPV6_MULTIPLE_TABLES
296a7f7f624SMasahiro Yamada	help
29746738b13SDavid Lebrun	  Support for encapsulation of packets within an outer IPv6
29846738b13SDavid Lebrun	  header and a Segment Routing Header using the lightweight
299d1df6fd8SDavid Lebrun	  tunnels mechanism. Also enable support for advanced local
300d1df6fd8SDavid Lebrun	  processing of SRv6 packets based on their active segment.
30146738b13SDavid Lebrun
30246738b13SDavid Lebrun	  If unsure, say N.
30346738b13SDavid Lebrun
304bf355b8dSDavid Lebrunconfig IPV6_SEG6_HMAC
305bf355b8dSDavid Lebrun	bool "IPv6: Segment Routing HMAC support"
306bf355b8dSDavid Lebrun	depends on IPV6
307db7cd91aSNecip Fazil Yildiran	select CRYPTO
308bf355b8dSDavid Lebrun	select CRYPTO_HMAC
309bf355b8dSDavid Lebrun	select CRYPTO_SHA1
310bf355b8dSDavid Lebrun	select CRYPTO_SHA256
311a7f7f624SMasahiro Yamada	help
312bf355b8dSDavid Lebrun	  Support for HMAC signature generation and verification
313bf355b8dSDavid Lebrun	  of SR-enabled packets.
314bf355b8dSDavid Lebrun
315bf355b8dSDavid Lebrun	  If unsure, say N.
316bf355b8dSDavid Lebrun
317fe94cc29SMathieu Xhonneuxconfig IPV6_SEG6_BPF
318fe94cc29SMathieu Xhonneux	def_bool y
319fe94cc29SMathieu Xhonneux	depends on IPV6_SEG6_LWTUNNEL
320fe94cc29SMathieu Xhonneux	depends on IPV6 = y
321fe94cc29SMathieu Xhonneux
322a7a29f9cSAlexander Aringconfig IPV6_RPL_LWTUNNEL
323a7a29f9cSAlexander Aring	bool "IPv6: RPL Source Routing Header support"
324a7a29f9cSAlexander Aring	depends on IPV6
325a7a29f9cSAlexander Aring	select LWTUNNEL
326a7f7f624SMasahiro Yamada	help
327a7a29f9cSAlexander Aring	  Support for RFC6554 RPL Source Routing Header using the lightweight
328a7a29f9cSAlexander Aring	  tunnels mechanism.
329a7a29f9cSAlexander Aring
330a7a29f9cSAlexander Aring	  If unsure, say N.
331a7a29f9cSAlexander Aring
3323edede08SJustin Iurmanconfig IPV6_IOAM6_LWTUNNEL
3333edede08SJustin Iurman	bool "IPv6: IOAM Pre-allocated Trace insertion support"
3343edede08SJustin Iurman	depends on IPV6
3353edede08SJustin Iurman	select LWTUNNEL
3368cb3bf8bSJustin Iurman	select DST_CACHE
3373edede08SJustin Iurman	help
3388cb3bf8bSJustin Iurman	  Support for the insertion of IOAM Pre-allocated Trace
3398cb3bf8bSJustin Iurman	  Header using the lightweight tunnels mechanism.
3403edede08SJustin Iurman
3413edede08SJustin Iurman	  If unsure, say N.
3423edede08SJustin Iurman
3430b18542bSJan Engelhardtendif # IPV6
344