alarig@regis ~ $ ip a sh dev br0
7: br0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ee:50:27:2b:10:2c brd ff:ff:ff:ff:ff:ff
    inet 89.234.186.209/28 brd 89.234.186.223 scope global br0
       valid_lft forever preferred_lft forever
    inet6 2a00:5884:102:1::1/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::209/64 scope link
       valid_lft forever preferred_lft forever
    inet6 fe80::ec50:27ff:fe2b:102c/64 scope link
       valid_lft forever preferred_lft forever
alarig@regis ~ $ ping kaiminus.swordarmor.fr
PING kaiminus.swordarmor.fr (2a00:5884:102:1::7) 56 data bytes
64 bytes from kaiminus.swordarmor.fr (2a00:5884:102:1::7): icmp_seq=1 ttl=64 time=0.258 ms
64 bytes from kaiminus.swordarmor.fr (2a00:5884:102:1::7): icmp_seq=2 ttl=64 time=0.394 ms
^C
--- kaiminus.swordarmor.fr ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1182ms
rtt min/avg/max/mdev = 0.258/0.326/0.394/0.068 ms
alarig@regis ~ $ ip -6 r sh match 2a00:5884:102:1::7
2a00:5884:102:1::/64 dev br0 proto bird metric 32 pref medium
2a00:5884:102:1::/64 dev br0 proto kernel metric 256 pref medium
unreachable 2a00:5884:102::/48 dev lo proto bird metric 32 pref medium
2a00:5884::/32 via 2001:7f8:b1::d dev brvlan10 proto bird src 2a0e:f42:ffff::1 metric 32 pref medium
default via fe80::204:92:100:1 dev eno1.30 metric 1024 pref medium
alarig@regis ~ $ sysctl net.ipv6.conf.all.forwarding
net.ipv6.conf.all.forwarding = 1
alarig@regis ~ $ ip n sh 2a00:5884:102:1::7
2a00:5884:102:1::7 dev br0 lladdr 52:54:00:d5:df:7b REACHABLE
alarig@regis ~ $ ip n sh fe80::204:92:100:1 dev eno1.30
fe80::204:92:100:1 lladdr 00:00:5e:00:02:01 router REACHABLE
alarig@regis ~ $