Comment 79 for bug 1671951

I'm trying to understand if there is any work still required on this bug for cloud-init. I've tested two network configurations (in lxd containers). The first:

  version: 2
  ethernets:
    eth0:
      dhcp4: true
      dhcp6: true
      ipv6-mtu: 1337

As this is just a passthrough to netplan, this works as expected: /proc/sys/net/ipv6/conf/eth0/mtu is 1337, /sys/class/net/eth0/mtu is 1500.

The second:

  version: 1
  config:
      - type: physical
        name: eth0
        mtu: 1337
        subnets:
            - type: dhcp
            - type: dhcp6

Given that we don't have a separate setting for the IPv6-specific MTU, this seems to work as I expect: both /proc/sys/net/ipv6/conf/eth0/mtu and /sys/class/net/eth0/mtu are set to 1337. I'm not sure, however, that this is a sufficient test, or if my expectations are correct.

Thoughts, anyone?