Arch Linux

Cvlc

Member

Registered: 2020-03-26

Posts: 295

mDNS keeps switching off

Hi

I'm using NetworkManager (with Gnome), with iwd backend, and systemd-resolved for DNS. It's a laptop with both a WiFi connection and an Ethernet cable plugged in, connected to the same router.

The Wiki is a little confusing concerning mDNS. It says both that "By default systemd-resolved enables mDNS responder" and that "You will also need to enable it on each interface you want mDNS to work: systemd-resolve --set-mdns=yes --interface=name", which seems contradictory.

Indeed, I finally got mDNS to work by running "systemd-resolve --set-mdns=yes", having missed that step thinking it was enabled for systemd-resolved, and that I just had to deal with NM.

But it's behaving very strangely, when I disconnect WiFi or unplug the Ethernet cable, mDNS gets reset on the other connection. I cannot seem to understand a pattern, there probably is one but it just looks like bringing an interface up or down just randomly switches the thing. I check it with "resolvectl" and I see +mDNS or -mDNS.

Maybe I should be keeping only one of these connections alive at a time, but it seems to work well like this so I haven't found a reason to use something like this.

any ideas as to why mDNS gets switched off automatically ?

Thanks !