When I do a ping from the non working host, I do see the ping reply on the turris:
17:58:55.826997 IP6 2a02:842a:xxxx:xxxx::42 > 2a00:1450:4007:809::200e: ICMP6, echo request, seq 18, length 64
17:58:55.834171 IP6 2a00:1450:4007:809::200e > 2a02:842a:xxxx:xxxx::42: ICMP6, echo reply, seq 18, length 64
17:58:56.837043 IP6 2a02:842a:xxxx:xxxx::42 > 2a00:1450:4007:809::200e: ICMP6, echo request, seq 19, length 64
17:58:56.843028 IP6 2a00:1450:4007:809::200e > 2a02:842a:xxxx:xxxx::42: ICMP6, echo reply, seq 19, length 64
but it never reaches the host:
PING ipv6.google.com(par10s27-in-x0e.1e100.net (2a00:1450:4007:809::200e)) 56 data bytes
^C
--- ipv6.google.com ping statistics ---
22 packets transmitted, 0 received, 100% packet loss, time 21288ms
which is confirmed as I cannot see the reply when doing the tcpdump on br-lan instead of eth2:
18:04:56.482530 IP6 2a02:842a:xxxx:xxxx::42 > 2a00:1450:4007:809::200e: ICMP6, echo request, seq 1, length 64
18:04:57.503507 IP6 2a02:842a:xxxx:xxxx::42 > 2a00:1450:4007:809::200e: ICMP6, echo request, seq 2, length 64
At router boot, I get following routes:
default from 2a02:842a:xxxx:xx00::/56 via fe80::5555 dev eth2 proto static metric 512 pref medium
2a02:842a:xxxx:xx00::/64 dev br-lan proto static metric 1024 pref medium
unreachable 2a02:842a:xxxx:xx00::/56 dev lo proto static metric 2147483647 pref medium
fe80::/64 dev eth1 proto kernel metric 256 pref medium
fe80::/64 dev br-lan proto kernel metric 256 pref medium
fe80::/64 dev eth2 proto kernel metric 256 pref medium
fe80::/64 dev vethCmXxSc proto kernel metric 256 pref medium
After generating traffic from the non working host, I see an extra route which is strange:
default from 2a02:842a:xxxx:xx00::/56 via fe80::5555 dev eth2 proto static metric 512 pref medium
2a02:842a:xxxx:xx00::/64 dev br-lan proto static metric 1024 pref medium
2a02:842a:xxxx:xx04::/62 via fe80::xxxx:xxxx:xxxx:66b0 dev br-lan proto static metric 1024 pref medium
unreachable 2a02:842a:xxxx:xx00::/56 dev lo proto static metric 2147483647 pref medium
fe80::/64 dev eth1 proto kernel metric 256 pref medium
fe80::/64 dev br-lan proto kernel metric 256 pref medium
fe80::/64 dev eth2 proto kernel metric 256 pref medium
fe80::/64 dev vethCmXxSc proto kernel metric 256 pref medium
fe80::/64 dev ifb4eth2 proto kernel metric 256 pref medium
fe80::xxxx:xxxx:xxxx:66b0 belongs to the non working host.
Manually removing that route does not fix the issue.