I'm still seeing this issue with today's (Feb 4) snapshot. Using a comcast 6to4 tunnel.
Example test ping6 from Internet to one of my IPs.
pfSense (tcpdump -nl -i wan_stf icmp6) shows incoming, but not outgoing:
14:31:52.284810 IP6 2001:0:5ef5:79fb:207e:3990:a170:d7dd > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 46473, length 12
14:31:52.292372 IP6 2001:0:5ef5:79fd:147f:fc:4dd1:2871 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 61394, length 12
14:31:52.833067 IP6 2001:0:5ef5:79fd:24bd:11bb:3d61:b78e > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 17908, length 12
14:31:52.959949 IP6 2001:0:5ef5:79fd:348f:9fbc:a80b:4d9b > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 28153, length 12
14:31:53.004120 IP6 2001:0:5ef5:79fb:81e:159b:3e95:3495 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 65131, length 12
14:31:53.067017 IP6 2001:0:5ef5:79fd:1423:3282:aa11:814a > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 52250, length 12
14:31:53.163090 IP6 2001:0:5ef5:79fd:1073:2536:a0cb:edb1 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 49772, length 12
On the Linux host on my network, tcpdump -nl -i eth0 icmp6 shows requests and replies:
14:31:42.102136 IP6 2001:0:5ef5:79fd:3401:2abb:3dd3:a258 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 626, length 12
14:31:42.102182 IP6 2002:473b:fbe7:0:290:a9ff:feb2:c733 > 2001:0:5ef5:79fd:3401:2abb:3dd3:a258: ICMP6, echo reply, seq 626, length 12
14:31:42.109412 IP6 2001:0:5ef5:79fd:2caf:2133:b214:8883 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 20966, length 12
14:31:42.109449 IP6 2002:473b:fbe7:0:290:a9ff:feb2:c733 > 2001:0:5ef5:79fd:2caf:2133:b214:8883: ICMP6, echo reply, seq 20966, length 12
14:31:43.858917 IP6 2001:0:5ef5:79fd:3401:2abb:3dd3:a258 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 51208, length 12
14:31:43.858970 IP6 2002:473b:fbe7:0:290:a9ff:feb2:c733 > 2001:0:5ef5:79fd:3401:2abb:3dd3:a258: ICMP6, echo reply, seq 51208, length 12
14:31:44.112409 IP6 2001:0:5ef5:79fd:2caf:2133:b214:8883 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 36893, length 12
14:31:44.112453 IP6 2002:473b:fbe7:0:290:a9ff:feb2:c733 > 2001:0:5ef5:79fd:2caf:2133:b214:8883: ICMP6, echo reply, seq 36893, length 12
14:31:45.358902 IP6 2001:0:5ef5:79fb:b0:e9e:4d2d:e648 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 32159, length 12
14:31:45.358937 IP6 2002:473b:fbe7:0:290:a9ff:feb2:c733 > 2001:0:5ef5:79fb:b0:e9e:4d2d:e648: ICMP6, echo reply, seq 32159, length 12
14:31:45.568785 IP6 2001:0:5ef5:79fd:1c79:1642:a433:aa23 > 2002:473b:fbe7:0:290:a9ff:feb2:c733: ICMP6, echo request, seq 17157, length 12
14:31:45.568831 IP6 2002:473b:fbe7:0:290:a9ff:feb2:c733 > 2001:0:5ef5:79fd:1c79:1642:a433:aa23: ICMP6, echo reply, seq 17157, length 12
The same Linux host can initiate outgoing icmp6 traffic:
# ping6 ipv6.google.com
PING ipv6.google.com(pd-in-x68.1e100.net) 56 data bytes
64 bytes from pd-in-x68.1e100.net: icmp_seq=1 ttl=56 time=38.4 ms
64 bytes from pd-in-x68.1e100.net: icmp_seq=2 ttl=56 time=43.3 ms
64 bytes from pd-in-x68.1e100.net: icmp_seq=3 ttl=56 time=38.5 ms
^C
--- ipv6.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 38.463/40.130/43.354/2.280 ms
I have configured floating and interface-specific rules to allow ICMP6 from any source/destination. Not sure exactly how to troubleshoot this.