Avahi-daemon / ippfind / cups issue: can't add printers

Hi there,

I’m facing a new curious Issue on my Fedora 37 Installation. I discovered it while trying to add a new printer and it doesn’t get added at all. On the WebIF, It fails with the error “Unable to get list of printer drivers: Success”. I read something on stackexchange that it’s mostly a misconfigured driver, as lpinfo -m produces in some circumstances very large tables… But in my case, i discovered, that it has something to do with mDNS, because ippfind freezes, if i run it on the command line. So i temporary disabled avahi-daemon and cups is working again. And also, lpinfo -m works, of course.

but i couldn’t figure out what the root cause is. i created a vm in gnome boxes, installed fedora in it and have compared the avahi-configs and nsswitch.conf files, they are all the same. i even purged the cups configs and did a reinstall of cups but with no avail.

so, i hope, there are some avahi-gurus around who can help me :slight_smile:

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I am not sure what was going on here. The avahi server is used to tell other systems about available printers, but it is not strictly necessary if you don’t need or want this facility. If you have an AirPrint capable printer in your local network, it will register itself with avahi, and cups can automatically configure it. This, I guess, is not enabled out of the box.

So, if cups works for you and you can print, then that would be OK.

lpinfo -m does not talk to avahi; instead it talks to cups, so I am not sure why it would hang.

i think, it has something to do with driverless found in the cups-filters package, it talks to avahi. my workaround for now is to stop avahi while adding a new printer and restart them afterwards. i’ll try to reinstall the os on a weekend, while keeping /home. Thanks to btrfs, it shouldn’t take much time.

Btw Airprint / IPP / avahi is enabled by default. my WF-4820 printer is always there - without configuring anything. But it looks like not every application can deal with it, some wouldn’t show the printer, so i have to add them as jetdirect/socket. But this is another story :wink:

Oh my edits are lost somehow, the commands lpinfo -m and driverless needs 5min to complete, while cups timeout after 60 seconds while trying to add a printer…

Do you perhaps have a firewall issue, but that would also mean that your ipp-everywhere printer wouldn’t work either.

You can browse avahi directly using

avahi-browse -acr

I would expect that lpinfo -v rather than lpinfo -m would talk to avahi.

I did a reinstall. Since I wanted to switch to Silverblue anyway, this came just handy. Therefore, I can’t investigate this problem any further.