Public bug reported: When IPv6 ND RAs are sent from two different routers, one with Medium and one with High preferences, systemd-networkd will ignore the fact they have different preferences and create two multipath routes with the same weight.
I ran a tcpdump of the RAs and confirmed that both have different preferences sent. i.e. nms-mon1:~$ ip -6 route 2a0d:1a40:7551:6010::/64 dev ens18 proto ra metric 100 pref medium fe80::/64 dev ens18 proto kernel metric 256 pref medium default proto ra metric 100 nexthop via fe80::c030:9cff:fe10:3492 dev ens18 weight 1 nexthop via fe80::215:5dff:fe83:c81c dev ens18 weight 1 Ubuntu version: Ubuntu 18.04.4 LTS systemd version: 237-3ubuntu10.39 ** Affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1869961 Title: systemd-networkd ignores RA preference and creates multipath routes anyway To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1869961/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs