An update on this: it appears that this is NOT a bug in systemd-networkd - I managed to trigger the same behaviour in NetworkManager too, it just seemed to take a little longer.
I have also tested a number of kernels (4.15, 4.21, 5.0, 5.1, 5.2, 5.3, 5.4) and Ubuntu 20.04 but each results in connection issues between the cluster and the new node. I'm unsure what my next steps should be, maybe trying Debian or Centos. Any help to troubleshoot this problem is greatly appreciated! ** Summary changed: - high packet loss on 18.04 with systemd-networkd + high packet loss on 18.04 with systemd -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1886826 Title: high packet loss on 18.04 with systemd To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1886826/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs