@Balint, after further testing, here's where things are:
----------------- On LXD Containers ----------------- On Bionic 1) First boot: neither interface mtu, nor ipv6 mtu is applied. 2) Restarting systemd-networkd: neither interface nor ipv6-mtu is applied 3) netplan apply: interface mtu is set correctly, ipv6 mtu is not. On Disco 1) First boot: neither interface mtu, nor ipv6 mtu is applied. 2) Restarting systemd-networkd: neither interface nor ipv6-mtu is applied 3) netplan apply: both interface and ipv6 MTU are set correctly. On Eoan 1) First boot: neither interface mtu, nor ipv6 mtu is applied 2) Restarting systemd-networkd: neither interface nor ipv6-mtu is applied 3) netplan apply: both interface and ipv6 MTU are set correctly. ------ On VMs ------ On Bionic 1) First boot: interface MTU is set, ipv6 MTU is not applied. 2) Restarting systemd-networkd: both interface and ipv6 MTU are set correctly 3) netplan apply not needed 4) After reboot, same as (1) On Disco 1) First boot: interface MTU is set, ipv6 MTU is not applied. 2) Restarting systemd-networkd: both interface and ipv6 MTU are set correctly 3) netplan apply not needed 4) After reboot, same as (1) On Eoan 1) First boot: interface MTU is set, ipv6 MTU is not applied. 2) Restarting systemd-networkd: both interface and ipv6 MTU are set correctly 3) netplan apply not needed 4) After reboot, same as (1) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1671951 Title: networkd should allow configuring IPV6 MTU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1671951/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
