Comment 17 for bug 1874021

OK thanks for the updates. So I can see a lot of mDNS packets in the lp1874021.pcap capture from various sources. I can see some printers, google cast, sonoff, etc. Curiously though when you do the avahi cache dump it isn't seeing any of these.

Wireshark is showing malformed packets for many of the responses strangely, the IP and UDP headers indicate a different length to that of the actual dta. Not sure if this is an issue with wireshark, the wireless driver or whatever mDNS implementations are replying. May need further looking at.

But it's curious though that avahi is showing absoultely no cached services, and that it works on ethernet, given that the lp1874021.pcap seems to show plenty of actual mDNS packets coming and going.

Could you try start Avahi (on wireless) using --debug

(1) override the systemd config with this command:
systemctl edit avahi-daemon.service

Once the editor opens, add the following 3 lines then save and squit:

[Service]
ExecStart=
ExecStart=/usr/sbin/avahi-daemon -s --debug

Then restart avahi-daemon: sudo systemctl restart avahi-daemon.service

Lastly run "avahi-browse -av", wait a minute or two, then upload a copy of the "journalctl -u avahi-daemon" again?