mDNS (Avahi) unable to start caused by too long auto-config

TrueNAS General
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1

TrueNAS Scale ElectricEel-24.10.2.3

My avahi daemon was not restarting, I killed it and then it didn’t want to start at all (which makes sense I guess)

Kept getting this error

avahi-daemon[3986518]: Missing assignment in /etc/avahi/avahi-daemon.conf:24: <xxxxxxxx, br-xxxxxxxxxxxx, br-xxxxxxxxxxxx, br>

So I went to the file and line 24 was actually

allow-interfaces=enp3s0, vlanX, vlanX, br0

Turns out the auto-generated denied interfaces are way too long for the daemon and that causes the crash
My solution was to replace values deny-interfaces with wildcards

deny-interfaces=wg*, lo, tun*, tap*, docker*, veth*, vnet*, macvtap*, ix*, tailscale*, br-*

And now avahi starts normally

My only issue now is that every time I restart SMB (not often at all so not a big pain rn), the file gets overwritten and avahi fails to start again.

Is there any way of changing the allow/deny interfaces in the mDNS? I wasn’t able to find any info on this

1 Like
2

This is still happening in 25.04.2

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Looks like it’s fixed in 25.04.2.3

4

Is it? I just ran into this issue on 25.10.0.1

5

I get an mDNS error I’ve never been able to resolve when running the ChromecastBridge in the LMS docker app in TrueNAS in all versions v24 and v25. I wonder if this is the reason ?

My only workaround was to set up LMS in a Debian container rather than docker.

6

Just ran into this again after upgrading from 25.04.2.6 (General) to 25.10.0.1 (Early Adopter)

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i just ran into this in 25.10.1 .. removed all br- interfaces and replaced with br-* and was able to restart the with systemctl restart avahi-daemon

1 Like
8

Happened to me awhile ago, before it mdns works correctly.

‘br-*’ trick did work, but it brokes after truenas reboot.

9

I’m on 25.10.1 with exactly the same issue. Is there maybe already a bug report?

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If you find an open bug report or create one, post a link to it in this thread so it is easier to follow for all users.