How to prevent Avahi adding -2 to hostnames

Often (maybe 80% of the time), when I reboot a machine running Avahi, it starts using machinename-2.local as it's hostname. All the machines on my network have unique hostnames, so there is no collision.

How do I prevent Avahi from appending -2 to hostnames?

(This turns out to be an incredibly difficult thing to Google for...)

Solution 1:

This is also the case with OS X machines.

If the hostname is already in use on the network it bumps the counter to make the names unique again. I would suspect that the machine in question may have two netcards to the same network (cabled and wireless) or that you have a bonjour proxy running (which may be unknown to you) which helps sleeping machines by holding their hostname active. To be more certain you may want to describe your network better.

Solution 2:

In my case, this behavior is caused by a Plex Media Server inside a docker container which runs its own avahi-daemon. I'm using this docker image: https://hub.docker.com/r/linuxserver/plex/

The number was increased very often, without need to restart.

After stopping the docker container and a restart of avahi-daemon.service, the numbers disappeared.