it looks like your dhcp lease is expiring, which causes networkd to drop your dhcp configuration, including resetting your mtu back to its original value. That's done asynchronously by netlink, and networkd sets a flag "setting_mtu" while the netlink request to change the mtu is pending.
However, immediately after your lease is lost, you regain it, and networkd begins setting up the interface with the dhcp info, including the mtu. Unfortunately, since the mtu reset hasn't completed yet, "setting_mtu" flag is still set, and the call to link_set_mtu() returns silently without actually changing the mtu. At least that's what seems like is happening in your case. It's unusual to lose your dhcp lease before renewing it, so you may be able to look at why that's happening to avoid this (hopefully that's not a separate bug in systemd...), but re: the failure to set mtu, I believe that's going to be a problem that still exists upstream, so resolving this bug will need fixing upstream first. If you (or anyone else) has time to open a bug upstream for this (preferably, after testing with upstream systemd to verify it's still a bug upstream), please add a note to this bug. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1874661 Title: networkd sometimes doesn't set mtu received by dhcp To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1874661/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
