xref: /openbmc/linux/net/ipv6/Kconfig (revision 8cb3bf8b)
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
10a7f7f624SMasahiro Yamada	help
11de551f2eSTom Herbert	  Support for IP version 6 (IPv6).
126a2e9b73SSam Ravnborg
136a2e9b73SSam Ravnborg	  For general information about IPv6, see
14242260fbSChristian Kujau	  <https://en.wikipedia.org/wiki/IPv6>.
15de551f2eSTom Herbert	  For specific information about IPv6 under Linux, see
1619093313SMauro Carvalho Chehab	  Documentation/networking/ipv6.rst and read the HOWTO at
177a6498ebSAlexander A. Klimov	  <https://www.tldp.org/HOWTO/Linux+IPv6-HOWTO/>
186a2e9b73SSam Ravnborg
196a2e9b73SSam Ravnborg	  To compile this protocol support as a module, choose M here: the
206a2e9b73SSam Ravnborg	  module will be called ipv6.
216a2e9b73SSam Ravnborg
220b18542bSJan Engelhardtif IPV6
230b18542bSJan Engelhardt
24ebacaaa0SYOSHIFUJI Hideakiconfig IPV6_ROUTER_PREF
25ebacaaa0SYOSHIFUJI Hideaki	bool "IPv6: Router Preference (RFC 4191) support"
26a7f7f624SMasahiro Yamada	help
27ebacaaa0SYOSHIFUJI Hideaki	  Router Preference is an optional extension to the Router
28692105b8SMatt LaPlante	  Advertisement message which improves the ability of hosts
29692105b8SMatt LaPlante	  to pick an appropriate router, especially when the hosts
30692105b8SMatt LaPlante	  are placed in a multi-homed network.
31ebacaaa0SYOSHIFUJI Hideaki
32ebacaaa0SYOSHIFUJI Hideaki	  If unsure, say N.
33ebacaaa0SYOSHIFUJI Hideaki
3470ceb4f5SYOSHIFUJI Hideakiconfig IPV6_ROUTE_INFO
35f9ceb16eSKees Cook	bool "IPv6: Route Information (RFC 4191) support"
36f9ceb16eSKees Cook	depends on IPV6_ROUTER_PREF
37a7f7f624SMasahiro Yamada	help
38a9f71d0dSGeorg Hofmann	  Support of Route Information.
3970ceb4f5SYOSHIFUJI Hideaki
4070ceb4f5SYOSHIFUJI Hideaki	  If unsure, say N.
4170ceb4f5SYOSHIFUJI Hideaki
4295c385b4SNeil Hormanconfig IPV6_OPTIMISTIC_DAD
43f9ceb16eSKees Cook	bool "IPv6: Enable RFC 4429 Optimistic DAD"
44a7f7f624SMasahiro Yamada	help
45a9f71d0dSGeorg Hofmann	  Support for optimistic Duplicate Address Detection. It allows for
46a9f71d0dSGeorg Hofmann	  autoconfigured addresses to be used more quickly.
4795c385b4SNeil Horman
4895c385b4SNeil Horman	  If unsure, say N.
4995c385b4SNeil Horman
501da177e4SLinus Torvaldsconfig INET6_AH
511da177e4SLinus Torvalds	tristate "IPv6: AH transformation"
527d4e3919SEric Biggers	select XFRM_AH
53a7f7f624SMasahiro Yamada	help
54be013698SEric Biggers	  Support for IPsec AH (Authentication Header).
55be013698SEric Biggers
56be013698SEric Biggers	  AH can be used with various authentication algorithms.  Besides
57be013698SEric Biggers	  enabling AH support itself, this option enables the generic
58be013698SEric Biggers	  implementations of the algorithms that RFC 8221 lists as MUST be
59be013698SEric Biggers	  implemented.  If you need any other algorithms, you'll need to enable
60be013698SEric Biggers	  them in the crypto API.  You should also enable accelerated
61be013698SEric Biggers	  implementations of any needed algorithms when available.
621da177e4SLinus Torvalds
631da177e4SLinus Torvalds	  If unsure, say Y.
641da177e4SLinus Torvalds
651da177e4SLinus Torvaldsconfig INET6_ESP
661da177e4SLinus Torvalds	tristate "IPv6: ESP transformation"
677d4e3919SEric Biggers	select XFRM_ESP
68a7f7f624SMasahiro Yamada	help
69be013698SEric Biggers	  Support for IPsec ESP (Encapsulating Security Payload).
70be013698SEric Biggers
71be013698SEric Biggers	  ESP can be used with various encryption and authentication algorithms.
72be013698SEric Biggers	  Besides enabling ESP support itself, this option enables the generic
73be013698SEric Biggers	  implementations of the algorithms that RFC 8221 lists as MUST be
74be013698SEric Biggers	  implemented.  If you need any other algorithms, you'll need to enable
75be013698SEric Biggers	  them in the crypto API.  You should also enable accelerated
76be013698SEric Biggers	  implementations of any needed algorithms when available.
771da177e4SLinus Torvalds
781da177e4SLinus Torvalds	  If unsure, say Y.
791da177e4SLinus Torvalds
807785bba2SSteffen Klassertconfig INET6_ESP_OFFLOAD
817785bba2SSteffen Klassert	tristate "IPv6: ESP transformation offload"
827785bba2SSteffen Klassert	depends on INET6_ESP
837785bba2SSteffen Klassert	select XFRM_OFFLOAD
847785bba2SSteffen Klassert	default n
85a7f7f624SMasahiro Yamada	help
867785bba2SSteffen Klassert	  Support for ESP transformation offload. This makes sense
877785bba2SSteffen Klassert	  only if this system really does IPsec and want to do it
887785bba2SSteffen Klassert	  with high throughput. A typical desktop system does not
897785bba2SSteffen Klassert	  need it, even if it does IPsec.
907785bba2SSteffen Klassert
917785bba2SSteffen Klassert	  If unsure, say N.
927785bba2SSteffen Klassert
9326333c37SSabrina Dubrocaconfig INET6_ESPINTCP
9426333c37SSabrina Dubroca	bool "IPv6: ESP in TCP encapsulation (RFC 8229)"
9526333c37SSabrina Dubroca	depends on XFRM && INET6_ESP
9626333c37SSabrina Dubroca	select STREAM_PARSER
9726333c37SSabrina Dubroca	select NET_SOCK_MSG
9826333c37SSabrina Dubroca	select XFRM_ESPINTCP
9926333c37SSabrina Dubroca	help
10026333c37SSabrina Dubroca	  Support for RFC 8229 encapsulation of ESP and IKE over
10126333c37SSabrina Dubroca	  TCP/IPv6 sockets.
10226333c37SSabrina Dubroca
10326333c37SSabrina Dubroca	  If unsure, say N.
10426333c37SSabrina Dubroca
1051da177e4SLinus Torvaldsconfig INET6_IPCOMP
1061da177e4SLinus Torvalds	tristate "IPv6: IPComp transformation"
107d2acc347SHerbert Xu	select INET6_XFRM_TUNNEL
1086fccab67SHerbert Xu	select XFRM_IPCOMP
109a7f7f624SMasahiro Yamada	help
1101da177e4SLinus Torvalds	  Support for IP Payload Compression Protocol (IPComp) (RFC3173),
1111da177e4SLinus Torvalds	  typically needed for IPsec.
1121da177e4SLinus Torvalds
1131da177e4SLinus Torvalds	  If unsure, say Y.
1141da177e4SLinus Torvalds
115ee538268SMasahide NAKAMURAconfig IPV6_MIP6
116f9ceb16eSKees Cook	tristate "IPv6: Mobility"
117ee538268SMasahide NAKAMURA	select XFRM
118a7f7f624SMasahiro Yamada	help
119ee538268SMasahide NAKAMURA	  Support for IPv6 Mobility described in RFC 3775.
120ee538268SMasahide NAKAMURA
121ee538268SMasahide NAKAMURA	  If unsure, say N.
122ee538268SMasahide NAKAMURA
12365d7ab8dSTom Herbertconfig IPV6_ILA
12465d7ab8dSTom Herbert	tristate "IPv6: Identifier Locator Addressing (ILA)"
1258cb964daSArnd Bergmann	depends on NETFILTER
12683ed7d1fSArnd Bergmann	select DST_CACHE
12765d7ab8dSTom Herbert	select LWTUNNEL
128a7f7f624SMasahiro Yamada	help
12965d7ab8dSTom Herbert	  Support for IPv6 Identifier Locator Addressing (ILA).
13065d7ab8dSTom Herbert
13165d7ab8dSTom Herbert	  ILA is a mechanism to do network virtualization without
13265d7ab8dSTom Herbert	  encapsulation. The basic concept of ILA is that we split an
13365d7ab8dSTom Herbert	  IPv6 address into a 64 bit locator and 64 bit identifier. The
13465d7ab8dSTom Herbert	  identifier is the identity of an entity in communication
13565d7ab8dSTom Herbert	  ("who") and the locator expresses the location of the
13665d7ab8dSTom Herbert	  entity ("where").
13765d7ab8dSTom Herbert
13865d7ab8dSTom Herbert	  ILA can be configured using the "encap ila" option with
13965d7ab8dSTom Herbert	  "ip -6 route" command. ILA is described in
14065d7ab8dSTom Herbert	  https://tools.ietf.org/html/draft-herbert-nvo3-ila-00.
14165d7ab8dSTom Herbert
14265d7ab8dSTom Herbert	  If unsure, say N.
14365d7ab8dSTom Herbert
144d2acc347SHerbert Xuconfig INET6_XFRM_TUNNEL
145d2acc347SHerbert Xu	tristate
146d2acc347SHerbert Xu	select INET6_TUNNEL
147d2acc347SHerbert Xu	default n
1481da177e4SLinus Torvalds
149d2acc347SHerbert Xuconfig INET6_TUNNEL
150d2acc347SHerbert Xu	tristate
151d2acc347SHerbert Xu	default n
1521da177e4SLinus Torvalds
153ed1efb2aSSteffen Klassertconfig IPV6_VTI
154ed1efb2aSSteffen Klasserttristate "Virtual (secure) IPv6: tunneling"
155ed1efb2aSSteffen Klassert	select IPV6_TUNNEL
156876fc03aSSteffen Klassert	select NET_IP_TUNNEL
1574c145dceSFlorian Westphal	select XFRM
158a7f7f624SMasahiro Yamada	help
159ed1efb2aSSteffen Klassert	Tunneling means encapsulating data of one protocol type within
160ed1efb2aSSteffen Klassert	another protocol and sending it over a channel that understands the
161ed1efb2aSSteffen Klassert	encapsulating protocol. This can be used with xfrm mode tunnel to give
162ed1efb2aSSteffen Klassert	the notion of a secure tunnel for IPSEC and then use routing protocol
163ed1efb2aSSteffen Klassert	on top.
164ed1efb2aSSteffen Klassert
165989e5b96SJoerg Roedelconfig IPV6_SIT
166989e5b96SJoerg Roedel	tristate "IPv6: IPv6-in-IPv4 tunnel (SIT driver)"
167c73cb5a2SKazunori MIYAZAWA	select INET_TUNNEL
168f61dd388SPravin B Shelar	select NET_IP_TUNNEL
169de357cc0SYOSHIFUJI Hideaki	select IPV6_NDISC_NODETYPE
170989e5b96SJoerg Roedel	default y
171a7f7f624SMasahiro Yamada	help
172989e5b96SJoerg Roedel	  Tunneling means encapsulating data of one protocol type within
173989e5b96SJoerg Roedel	  another protocol and sending it over a channel that understands the
174989e5b96SJoerg Roedel	  encapsulating protocol. This driver implements encapsulation of IPv6
1755c5d6dabSDavid S. Miller	  into IPv4 packets. This is useful if you want to connect two IPv6
176989e5b96SJoerg Roedel	  networks over an IPv4-only path.
177989e5b96SJoerg Roedel
1784737f097SPavel Machek	  Saying M here will produce a module called sit. If unsure, say Y.
179989e5b96SJoerg Roedel
180fa857afcSYOSHIFUJI Hideaki / 吉藤英明config IPV6_SIT_6RD
181f9ceb16eSKees Cook	bool "IPv6: IPv6 Rapid Deployment (6RD)"
182f9ceb16eSKees Cook	depends on IPV6_SIT
183fa857afcSYOSHIFUJI Hideaki / 吉藤英明	default n
184a7f7f624SMasahiro Yamada	help
185fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  IPv6 Rapid Deployment (6rd; draft-ietf-softwire-ipv6-6rd) builds upon
186fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  mechanisms of 6to4 (RFC3056) to enable a service provider to rapidly
187fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  deploy IPv6 unicast service to IPv4 sites to which it provides
188fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  customer premise equipment.  Like 6to4, it utilizes stateless IPv6 in
189fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  IPv4 encapsulation in order to transit IPv4-only network
190fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  infrastructure.  Unlike 6to4, a 6rd service provider uses an IPv6
191fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  prefix of its own in place of the fixed 6to4 prefix.
192fa857afcSYOSHIFUJI Hideaki / 吉藤英明
193fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  With this option enabled, the SIT driver offers 6rd functionality by
194fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  providing additional ioctl API to configure the IPv6 Prefix for in
195fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  stead of static 2002::/16 for 6to4.
196fa857afcSYOSHIFUJI Hideaki / 吉藤英明
197fa857afcSYOSHIFUJI Hideaki / 吉藤英明	  If unsure, say N.
198fa857afcSYOSHIFUJI Hideaki / 吉藤英明
199de357cc0SYOSHIFUJI Hideakiconfig IPV6_NDISC_NODETYPE
200de357cc0SYOSHIFUJI Hideaki	bool
201de357cc0SYOSHIFUJI Hideaki
2021da177e4SLinus Torvaldsconfig IPV6_TUNNEL
20338fe999eSYOSHIFUJI Hideaki	tristate "IPv6: IP-in-IPv6 tunnel (RFC2473)"
204d2acc347SHerbert Xu	select INET6_TUNNEL
205607f725fSPaolo Abeni	select DST_CACHE
20697e219b7SEric Dumazet	select GRO_CELLS
207a7f7f624SMasahiro Yamada	help
20838fe999eSYOSHIFUJI Hideaki	  Support for IPv6-in-IPv6 and IPv4-in-IPv6 tunnels described in
20938fe999eSYOSHIFUJI Hideaki	  RFC 2473.
2101da177e4SLinus Torvalds
2111da177e4SLinus Torvalds	  If unsure, say N.
2121da177e4SLinus Torvalds
213c12b395aSxeb@mail.ruconfig IPV6_GRE
214c12b395aSxeb@mail.ru	tristate "IPv6: GRE tunnel"
215c12b395aSxeb@mail.ru	select IPV6_TUNNEL
216f61dd388SPravin B Shelar	select NET_IP_TUNNEL
2178bf42e9eSArnd Bergmann	depends on NET_IPGRE_DEMUX
218a7f7f624SMasahiro Yamada	help
219c12b395aSxeb@mail.ru	  Tunneling means encapsulating data of one protocol type within
220c12b395aSxeb@mail.ru	  another protocol and sending it over a channel that understands the
221c12b395aSxeb@mail.ru	  encapsulating protocol. This particular tunneling driver implements
222c12b395aSxeb@mail.ru	  GRE (Generic Routing Encapsulation) and at this time allows
223c12b395aSxeb@mail.ru	  encapsulating of IPv4 or IPv6 over existing IPv6 infrastructure.
224c12b395aSxeb@mail.ru	  This driver is useful if the other endpoint is a Cisco router: Cisco
225c12b395aSxeb@mail.ru	  likes GRE much better than the other Linux tunneling driver ("IP
226c12b395aSxeb@mail.ru	  tunneling" above). In addition, GRE allows multicast redistribution
227c12b395aSxeb@mail.ru	  through the tunnel.
228c12b395aSxeb@mail.ru
229c12b395aSxeb@mail.ru	  Saying M here will produce a module called ip6_gre. If unsure, say N.
230c12b395aSxeb@mail.ru
231fabb13dbSArnd Bergmannconfig IPV6_FOU
232fabb13dbSArnd Bergmann	tristate
233fabb13dbSArnd Bergmann	default NET_FOU && IPV6
234fabb13dbSArnd Bergmann
235fabb13dbSArnd Bergmannconfig IPV6_FOU_TUNNEL
236fabb13dbSArnd Bergmann	tristate
237fabb13dbSArnd Bergmann	default NET_FOU_IP_TUNNELS && IPV6_FOU
23895e4daa8SArnd Bergmann	select IPV6_TUNNEL
239fabb13dbSArnd Bergmann
240264e91b6SVille Nuorvalaconfig IPV6_MULTIPLE_TABLES
241264e91b6SVille Nuorvala	bool "IPv6: Multiple Routing Tables"
242264e91b6SVille Nuorvala	select FIB_RULES
243a7f7f624SMasahiro Yamada	help
244264e91b6SVille Nuorvala	  Support multiple routing tables.
245264e91b6SVille Nuorvala
2464e96c2b4SYOSHIFUJI Hideakiconfig IPV6_SUBTREES
2474e96c2b4SYOSHIFUJI Hideaki	bool "IPv6: source address based routing"
248264e91b6SVille Nuorvala	depends on IPV6_MULTIPLE_TABLES
249a7f7f624SMasahiro Yamada	help
2504e96c2b4SYOSHIFUJI Hideaki	  Enable routing by source address or prefix.
2514e96c2b4SYOSHIFUJI Hideaki
2524e96c2b4SYOSHIFUJI Hideaki	  The destination address is still the primary routing key, so mixing
2534e96c2b4SYOSHIFUJI Hideaki	  normal and source prefix specific routes in the same routing table
2544e96c2b4SYOSHIFUJI Hideaki	  may sometimes lead to unintended routing behavior.  This can be
2554e96c2b4SYOSHIFUJI Hideaki	  avoided by defining different routing tables for the normal and
2564e96c2b4SYOSHIFUJI Hideaki	  source prefix specific routes.
2574e96c2b4SYOSHIFUJI Hideaki
2584e96c2b4SYOSHIFUJI Hideaki	  If unsure, say N.
2594e96c2b4SYOSHIFUJI Hideaki
2607bc570c8SYOSHIFUJI Hideakiconfig IPV6_MROUTE
261f9ceb16eSKees Cook	bool "IPv6: multicast routing"
262f9ceb16eSKees Cook	depends on IPV6
2636853f21fSYuval Mintz	select IP_MROUTE_COMMON
264a7f7f624SMasahiro Yamada	help
265a9f71d0dSGeorg Hofmann	  Support for IPv6 multicast forwarding.
2667bc570c8SYOSHIFUJI Hideaki	  If unsure, say N.
2677bc570c8SYOSHIFUJI Hideaki
268d1db275dSPatrick McHardyconfig IPV6_MROUTE_MULTIPLE_TABLES
269d1db275dSPatrick McHardy	bool "IPv6: multicast policy routing"
270d1db275dSPatrick McHardy	depends on IPV6_MROUTE
271d1db275dSPatrick McHardy	select FIB_RULES
272d1db275dSPatrick McHardy	help
273d1db275dSPatrick McHardy	  Normally, a multicast router runs a userspace daemon and decides
274d1db275dSPatrick McHardy	  what to do with a multicast packet based on the source and
275d1db275dSPatrick McHardy	  destination addresses. If you say Y here, the multicast router
276d1db275dSPatrick McHardy	  will also be able to take interfaces and packet marks into
277d1db275dSPatrick McHardy	  account and run multiple instances of userspace daemons
278d1db275dSPatrick McHardy	  simultaneously, each one handling a single table.
279d1db275dSPatrick McHardy
280d1db275dSPatrick McHardy	  If unsure, say N.
281d1db275dSPatrick McHardy
28214fb64e1SYOSHIFUJI Hideakiconfig IPV6_PIMSM_V2
283f9ceb16eSKees Cook	bool "IPv6: PIM-SM version 2 support"
28414fb64e1SYOSHIFUJI Hideaki	depends on IPV6_MROUTE
285a7f7f624SMasahiro Yamada	help
28614fb64e1SYOSHIFUJI Hideaki	  Support for IPv6 PIM multicast routing protocol PIM-SMv2.
28714fb64e1SYOSHIFUJI Hideaki	  If unsure, say N.
28814fb64e1SYOSHIFUJI Hideaki
28946738b13SDavid Lebrunconfig IPV6_SEG6_LWTUNNEL
29046738b13SDavid Lebrun	bool "IPv6: Segment Routing Header encapsulation support"
29146738b13SDavid Lebrun	depends on IPV6
29246738b13SDavid Lebrun	select LWTUNNEL
293402a5bc4SDavid Lebrun	select DST_CACHE
294d7a669ddSDavid Lebrun	select IPV6_MULTIPLE_TABLES
295a7f7f624SMasahiro Yamada	help
29646738b13SDavid Lebrun	  Support for encapsulation of packets within an outer IPv6
29746738b13SDavid Lebrun	  header and a Segment Routing Header using the lightweight
298d1df6fd8SDavid Lebrun	  tunnels mechanism. Also enable support for advanced local
299d1df6fd8SDavid Lebrun	  processing of SRv6 packets based on their active segment.
30046738b13SDavid Lebrun
30146738b13SDavid Lebrun	  If unsure, say N.
30246738b13SDavid Lebrun
303bf355b8dSDavid Lebrunconfig IPV6_SEG6_HMAC
304bf355b8dSDavid Lebrun	bool "IPv6: Segment Routing HMAC support"
305bf355b8dSDavid Lebrun	depends on IPV6
306db7cd91aSNecip Fazil Yildiran	select CRYPTO
307bf355b8dSDavid Lebrun	select CRYPTO_HMAC
308bf355b8dSDavid Lebrun	select CRYPTO_SHA1
309bf355b8dSDavid Lebrun	select CRYPTO_SHA256
310a7f7f624SMasahiro Yamada	help
311bf355b8dSDavid Lebrun	  Support for HMAC signature generation and verification
312bf355b8dSDavid Lebrun	  of SR-enabled packets.
313bf355b8dSDavid Lebrun
314bf355b8dSDavid Lebrun	  If unsure, say N.
315bf355b8dSDavid Lebrun
316fe94cc29SMathieu Xhonneuxconfig IPV6_SEG6_BPF
317fe94cc29SMathieu Xhonneux	def_bool y
318fe94cc29SMathieu Xhonneux	depends on IPV6_SEG6_LWTUNNEL
319fe94cc29SMathieu Xhonneux	depends on IPV6 = y
320fe94cc29SMathieu Xhonneux
321a7a29f9cSAlexander Aringconfig IPV6_RPL_LWTUNNEL
322a7a29f9cSAlexander Aring	bool "IPv6: RPL Source Routing Header support"
323a7a29f9cSAlexander Aring	depends on IPV6
324a7a29f9cSAlexander Aring	select LWTUNNEL
325a7f7f624SMasahiro Yamada	help
326a7a29f9cSAlexander Aring	  Support for RFC6554 RPL Source Routing Header using the lightweight
327a7a29f9cSAlexander Aring	  tunnels mechanism.
328a7a29f9cSAlexander Aring
329a7a29f9cSAlexander Aring	  If unsure, say N.
330a7a29f9cSAlexander Aring
3313edede08SJustin Iurmanconfig IPV6_IOAM6_LWTUNNEL
3323edede08SJustin Iurman	bool "IPv6: IOAM Pre-allocated Trace insertion support"
3333edede08SJustin Iurman	depends on IPV6
3343edede08SJustin Iurman	select LWTUNNEL
335*8cb3bf8bSJustin Iurman	select DST_CACHE
3363edede08SJustin Iurman	help
337*8cb3bf8bSJustin Iurman	  Support for the insertion of IOAM Pre-allocated Trace
338*8cb3bf8bSJustin Iurman	  Header using the lightweight tunnels mechanism.
3393edede08SJustin Iurman
3403edede08SJustin Iurman	  If unsure, say N.
3413edede08SJustin Iurman
3420b18542bSJan Engelhardtendif # IPV6
343