After ifdown on underlay interface ifup fails with 'already configured'

[Witold Krecicki]

With following setup:
<...>
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:86:31:a8 brd ff:ff:ff:ff:ff:ff
    inet 10.245.40.80/18 brd 10.245.63.255 scope global ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::250:56ff:fe86:31a8/64 scope link
       valid_lft forever preferred_lft forever
<...>
4: fan-254: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UP group default qlen 1000
    link/ether 8a:f3:53:e5:11:37 brd ff:ff:ff:ff:ff:ff
    inet 254.161.64.1/8 scope global fan-254
       valid_lft forever preferred_lft forever
    inet6 fe80::88f3:53ff:fee5:1137/64 scope link
       valid_lft forever preferred_lft forever
5: ftun0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master fan-254 state UNKNOWN group default qlen 1000
    link/ether 8a:f3:53:e5:11:37 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::88f3:53ff:fee5:1137/64 scope link
       valid_lft forever preferred_lft forever

Doing ifdown ens192; ifup ens192 results in an error:
# ifdown ens192; echo $?; ifup ens192; echo $?
Killed old client process
<... isc-dhcp stuff ...>
0
<... isc-dhcp stuff ...>
/usr/sbin/fanctl: fan-254: already configured
/usr/sbin/fanctl: /etc/network/fan:40 10.245.0.0/18 254.0.0.0/8 -- failed err=1
run-parts: /etc/network/if-up.d/ubuntu-fan exited with return code 1
Failed to bring up ens192.
1

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-fan - 0.12.10

---------------
ubuntu-fan (0.12.10) bionic; urgency=medium

  * fan-net: support systemd-networkd controlled interfaces (LP: #1718227)
  * fanctl: Fix net stop internal command (LP: #1744296)
  * fan-net: Harden networkctl usage (LP: #1718227)
  * ifupdown/ubuntu-fan: Test for missing fanctl (LP: #1742712)

 -- Stefan Bader <email address hidden> Fri, 16 Mar 2018 11:47:46 +0100