Gigaclear & ip6 - lose of connectivity after *exactly* 5 minutes

ahxcjay

The only way I can have v6 connectivity last >24h05m00s is by:

route -6 add -host 2a02:fb8::11 -interface igb0
ndp -s 2a02:fb8::11 4e:6d:58:87:10:17 permanent

Without adding the permanent ndp entry, it defaults to 24 hours, then 5 minutes after the logs you see above, v6 dies. Once I add the permanent ndp entry I can go past 24 hours.

marcosm

@Irata

When a WAN only has a local-link IPv6 address, pfsense should be using this as the source address of neighbor advertisement messages, not picking a random LAN interface as the source address.

I tested this on 25.03 and pfSense always sent NA's sourced with the correct link-local address. This sounds more like there may be some routing/NAT issue. There's a default rule that allows any source/destination though so it should go through regardless.

Regarding https://redmine.pfsense.org/issues/16123#note-3
I see the ISP device sending NS for pfSense's link-local address without a response from pfSense:

138	2025-04-04 01:51:01.778710	0.020680	2a02:fb8::11	ff02::1:ff21:6b74	ICMPv6	86	Neighbor Solicitation for fe80::6662:66ff:fe21:6b74 from 4e:6d:58:87:10:17
145	2025-04-04 01:51:04.730835	0.972840	2a02:fb8::11	ff02::1:ff21:6b74	ICMPv6	86	Neighbor Solicitation for fe80::6662:66ff:fe21:6b74 from 4e:6d:58:87:10:17
152	2025-04-04 01:51:07.730711	0.359749	2a02:fb8::11	ff02::1:ff21:6b74	ICMPv6	86	Neighbor Solicitation for fe80::6662:66ff:fe21:6b74 from 4e:6d:58:87:10:17
209	2025-04-04 01:51:11.150835	0.015817	2a02:fb8::11	ff02::1:ff21:6b74	ICMPv6	86	Neighbor Solicitation for fe80::6662:66ff:fe21:6b74 from 4e:6d:58:87:10:17
214	2025-04-04 01:51:14.138711	1.003684	2a02:fb8::11	ff02::1:ff21:6b74	ICMPv6	86	Neighbor Solicitation for fe80::6662:66ff:fe21:6b74 from 4e:6d:58:87:10:17

While this is happening, check that pfSense has joined the respective multicast group with ifmcstat -i igc0 -f inet6. If it has joined as expected then it should show something like:

inet6 fe80::6662:66ff:fe21:6b74%igc0 scopeid 0x3
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
...
        group ff02::1:ff21:6b74%igc0 scopeid 0x3 mode exclude
                mcast-macaddr 33:33:ff:21:6b:74

A similar issue which has since been fixed exists in old versions:
https://redmine.pfsense.org/issues/13423