I have defined a subnetwork on my server, using ip aliases for a single ethernet card. Today, after a reboot, the avahi daemon is not resolving host names anymore.
The hosts defined in /etc/avahi/hosts:
172.17.0.10 loki.local
172.17.0.11 thor.local
172.17.0.12 odin.local
172.17.0.13 brunhild.local
172.17.0.14 heimdall.local
172.17.0.15 baldr.local
172.17.0.16 freyja.local
172.17.0.17 tyr.local
and the daemon.log after avahi is restarted:
Feb 2 16:42:56 siegfried systemd[1]: Started Avahi mDNS/DNS-SD Stack.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Successfully called chroot().
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Successfully dropped remaining capabilities.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: No service file found in /etc/avahi/services.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname loki.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname thor.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname odin.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname brunhild.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname heimdall.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname baldr.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname freyja.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Loading new static hostname tyr.local.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Joining mDNS multicast group on interface vethbccab72.IPv6 with address fe80::d02a:f0ff:fe76:3d26.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: New relevant interface vethbccab72.IPv6 for mDNS.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Joining mDNS multicast group on interface docker0.IPv6 with address fe80::42:36ff:feb5:43ba.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: New relevant interface docker0.IPv6 for mDNS.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Joining mDNS multicast group on interface docker0.IPv4 with address 172.18.0.1.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: New relevant interface docker0.IPv4 for mDNS.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Joining mDNS multicast group on interface eno1.IPv6 with address fe80::3617:ebff:feeb:cbd6.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: New relevant interface eno1.IPv6 for mDNS.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Joining mDNS multicast group on interface eno1.IPv4 with address 172.17.0.18.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: New relevant interface eno1.IPv4 for mDNS.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Network interface enumeration completed.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for fe80::d02a:f0ff:fe76:3d26 on vethbccab72.*.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for fe80::42:36ff:feb5:43ba on docker0.*.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.18.0.1 on docker0.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for fe80::3617:ebff:feeb:cbd6 on eno1.*.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.18 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.17 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.16 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.15 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.14 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.13 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.12 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.11 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.10 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 172.17.0.9 on eno1.IPv4.
Feb 2 16:42:56 siegfried avahi-daemon[6922]: Registering new address record for 10.0.10.9 on eno1.IPv4.
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Server startup complete. Host name is siegfried.local. Local service cookie is 2939514779.
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name tyr.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name freyja.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name baldr.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name heimdall.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name brunhild.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name odin.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name thor.local: avahi_server_add_address failure: Local name collision
Feb 2 16:42:57 siegfried avahi-daemon[6922]: Static host name loki.local: avahi_server_add_address failure: Local name collision
So, it looks like avahi is starting Ok, and then removing the hosts afterwards. It also loads a lot of interfaces I don't need (IPv6, and the docker bridge network) but I don't know if that's part of the problem, and how to disable them.
It was ok before the last reboot (there were only 2 hosts, loki and thor), and the only major change is that I installed vsftpd on the host machine.
