[Bug 1852754] Re: networkd does not complete interface configuration if Link MTUBytes is set

[Dan Streetman]

ubuntu at lp1850704-b:~$ cat /etc/systemd/network/10-ens3.network 
[Match]
Name=ens3

[Network]
DHCP=ipv4
LinkLocalAddressing=ipv6

[Link]
MTUBytes=6666

ubuntu at lp1850704-b:~$ dpkg -l systemd|grep ii
ii  systemd        237-3ubuntu10.33 amd64        system and service manager
ubuntu at lp1850704-b:~$ sudo systemctl restart systemd-networkd
ubuntu at lp1850704-b:~$ ip a show dev ens3
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 6666 qdisc fq_codel state UP group default qlen 1000
    link/ether 52:54:00:86:c7:44 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.197/24 brd 192.168.122.255 scope global dynamic ens3
       valid_lft 3596sec preferred_lft 3596sec
    inet6 fe80::5054:ff:fe86:c744/64 scope link 
       valid_lft forever preferred_lft forever

ubuntu at lp1850704-b:~$ networkctl | grep ens3
  2 ens3             ether              routable    configured


** Tags removed: verification-needed verification-needed-bionic
** Tags added: verification-done verification-done-bionic

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1852754

Title:
  networkd does not complete interface configuration if Link MTUBytes is
  set

Status in systemd:
  Fix Released
Status in systemd package in Ubuntu:
  Fix Released
Status in systemd source package in Bionic:
  Fix Committed

Bug description:
  [impact]

  interfaces configured with .network file [Link] section specifying
  MTUBytes will not be successfully brought up.

  [test case]

  configure interface e.g.

  Name=ens3

  [Network]
  DHCP=ipv4
  LinkLocalAddressing=ipv6

  [Link]
  MTUBytes=1550

  start/restart networkd, the interface will never reach 'routable'
  stage and will not get an IPv4 address.

  [regression potential]

  any regressions would likely occur during networkd
  configuration/startup/restart, and would likely cause failure to
  successfully setup the interface.

  [other info]

  this is a regression-proposed caused by incomplete backport for bug
  1850704

To manage notifications about this bug go to:
https://bugs.launchpad.net/systemd/+bug/1852754/+subscriptions