IPv6 no default gateway over GIF interface

djonk · Oct 16, 2022, 1:27 AM

Hi!

I've setup an IPv6 GIF tunnel with he.net tunnel broker. Generally the tunnel works fine and traffic flows. pfSense 2.7.0-DEVELOPMENT (amd64) does not honor the default gateway setting for IPv6.

Please find the settings and IPv6 routing table below.

Internet6:
Destination                       Gateway                       Flags     Netif Expire
::1                               link#5                        UHS         lo0
2001:470:c:XXX::1                 link#11                       UHS        gif0
2001:470:c:XXX::2                 link#11                       UHS         lo0
2001:470:d:YYY::/64               link#8                        U      vtnet0.1
2001:470:d:YYY::1                 link#8                        UHS         lo0
fe80::%vtnet0/64                  link#1                        U        vtnet0
fe80::b474:bfff:fe61:c8e5%vtnet0  link#1                        UHS         lo0
fe80::%vtnet1/64                  link#2                        U        vtnet1
fe80::8402:52ff:fef0:4638%vtnet1  link#2                        UHS         lo0
fe80::%vtnet2/64                  link#3                        U        vtnet2
fe80::bce7:bbff:fe6f:3bfa%vtnet2  link#3                        UHS         lo0
fe80::%lo0/64                     link#5                        U           lo0
fe80::1%lo0                       link#5                        UHS         lo0
fe80::%vtnet0.10/64               link#8                        U      vtnet0.1
fe80::b474:bfff:fe61:c8e5%vtnet0.10 link#8                      UHS         lo0
fe80::%vtnet0.20/64               link#9                        U      vtnet0.2
fe80::b474:bfff:fe61:c8e5%vtnet0.20 link#9                      UHS         lo0
fe80::%vtnet0.40/64               link#10                       U      vtnet0.4
fe80::b474:bfff:fe61:c8e5%vtnet0.40 link#10                     UHS         lo0
fe80::%gif0/64                    link#11                       U          gif0
fe80::40d3:5bf6:a295:d3d0%gif0    link#11                       UHS         lo0

Naturally there is no traffic flowing except to the statically defined route.

[2.7.0-DEVELOPMENT][admin@XXXX]/root: ping6 ipv6.google.com
ping6: UDP connect: No route to host
[2.7.0-DEVELOPMENT][admin@fw.XXXX]/root: ping6 2001:470:c:XXX::1 
PING6(56=40+8+8 bytes) 2001:470:c:XXX::2 --> 2001:470:c:XXX::1
16 bytes from 2001:470:c:XXX::1, icmp_seq=0 hlim=64 time=4.042 ms
16 bytes from 2001:470:c:XXX::1, icmp_seq=1 hlim=64 time=3.633 ms
16 bytes from 2001:470:c:XXX::1, icmp_seq=2 hlim=64 time=3.444 ms
^C
--- 2001:470:c:8d2::1 ping6 statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 3.444/3.706/4.042/0.250 ms

Manually setting the GIF0 interface as the inet6 default gateway resolves the issue.

[2.7.0-DEVELOPMENT][admin@fw.XXXX]/root: route add -inet6 default -interface gif0
add net default: gateway gif0
[2.7.0-DEVELOPMENT][admin@fw.XXXX]/root: ping6 ipv6.google.com
PING6(56=40+8+8 bytes) 2001:470:c:XXX::2 --> 2607:f8b0:4007:819::200e
16 bytes from 2607:f8b0:4007:819::200e, icmp_seq=0 hlim=120 time=4.143 ms
16 bytes from 2607:f8b0:4007:819::200e, icmp_seq=1 hlim=120 time=3.850 ms
16 bytes from 2607:f8b0:4007:819::200e, icmp_seq=2 hlim=120 time=2.734 ms
^C
--- ipv6.l.google.com ping6 statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 2.734/3.576/4.143/0.607 ms