5

After upgrading my Ubuntu 16.04 LTS virtual server the network didn't come up any more and server was unreachable.

My provider had to uncomment the line

/usr/sbin/fanctl net "$MODE" "$IFACE"

to get things running again. Is this a known bug?

3

I had this happen after I installed and later removed Docker. The Docker daemon depends on FAN so it gets installed, but if you don't purge it upon removal the startup script in /etc/network/if-up.d/ sticks around. Remove it with apt remove --purge ubuntu-fan.

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  • Maybe give a reason for the downvote? – Drew Stephens Jan 29 '18 at 19:13
4

The program you mentioned is packaged as ubuntu-fan. It was a dependency of Docker:

$ apt-cache rdepends ubuntu-fan
ubuntu-fan
Reverse Depends:
  docker.io
  docker.io

FAN is an IP over IP tunnel protocol which does network range remapping. This wiki page seems to be related.

This package has the following files:

$ apt-file list ubuntu-fan
ubuntu-fan: /etc/NetworkManager/conf.d/10-ubuntu-fan.conf
ubuntu-fan: /etc/default/ubuntu-fan
ubuntu-fan: /etc/dnsmasq.d/ubuntu-fan
ubuntu-fan: /etc/init.d/ubuntu-fan
ubuntu-fan: /etc/init/ubuntu-fan.conf
ubuntu-fan: /etc/network/if-down.d/ubuntu-fan
ubuntu-fan: /etc/network/if-post-down.d/ubuntu-fan
ubuntu-fan: /etc/network/if-up.d/ubuntu-fan # <<<<<
ubuntu-fan: /lib/systemd/system/ubuntu-fan.service
ubuntu-fan: /usr/lib/ubuntu-fan/fan-net
ubuntu-fan: /usr/sbin/fanatic
ubuntu-fan: /usr/sbin/fanctl
ubuntu-fan: /usr/share/doc/ubuntu-fan/README
ubuntu-fan: /usr/share/doc/ubuntu-fan/changelog.gz
ubuntu-fan: /usr/share/doc/ubuntu-fan/copyright
ubuntu-fan: /usr/share/man/man8/fanatic.8.gz
ubuntu-fan: /usr/share/man/man8/fanctl.8.gz
ubuntu-fan: /var/lib/ubuntu-fan/config/README

The file /etc/network/if-up.d/ubuntu-fan should be installed by default. It may be accidentally removed. You may want to purge this package and reinstall it back.

Its dependencies are listed on packages.ubuntu.com. It seems to be pulled as recommendation for docker.io package. Virtual servers usually have Docker installed.

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  • Thank you for looking into this. The server is a virtual server - it has no fan and needs no fan control. I wonder how there was some mention of the fan issue in the first place. – Wolfgang Fahl Dec 28 '17 at 19:29
  • It is FAN, not fan (from package description "FAN is an IP over IP tunnel protocol which does network range remapping."). This wiki page seems to be related. – N0rbert Dec 28 '17 at 19:34
  • Sorry for misinterpreting the TLA (Three Letter Acronym). I still wonder why the server would hang after an upgrade. Why would I need to install this package? What dependencies does it have? I did an apt-get autoremove and may be that remove it since some dependency is not properly documented in the Ubuntu 16.04 LTS distribution. So is it a bug? – Wolfgang Fahl Dec 28 '17 at 19:50
  • I do not know this FAN. Its dependencies are listed on packages.ubuntu.com. It seems to be pulled as recommendation for docker.io package. – N0rbert Dec 28 '17 at 19:52
  • 1
    please edit your answer / approve my edit. – Wolfgang Fahl Dec 28 '17 at 19:58

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