Simple things first: Have you checked that there is no firewall in between? By default, all network devices are assigned to the external zone, which blocks all ports. The machine connected to the printer should have its network interface assigned to the internal zone, provided it is connected to a secure private network.
I didn’t have changed the default parameters on the firewall. I’ve uploaded a ss as how it looks right now from YaST.
Is there a way to check in cli if the firewall is blocking this service? Also i’ve made a custom rule, all my network is added as an exception to the firewall.
I’ve found what I was doing wrong, I’ve made the firewall rule in the “internal zone” to allow from port 631 but it has to be made in the “external zone” that was quite confusing, I thought external zone was from outside the wan, but is outside the computer (in this case the computer that has the printer installed)
Its solved, if helps someone i’ve made a custom rule in firewall, example if your network is 192.168.0.1/24 I put 192.168.0.0/24 and then specified the port 631 (ipp) in the external zone, not in internal.
Glad you figured it out. However, the help text in the Yast-Printer module specifically advises against this sort of thing, but that said, probably a lot of people do it.
The firewall zones Internal / Demilitarized / External are just three settings for the firewall. You decide on the first page of the Yast-Firewall module which network interface belongs to which zones - it does not decide this on its own. This makes sense if you have multiple network connections: for example, a laptop’s wired interface might be assgined to the internal zone, while the wireless network interfaces is assigned to the external zone. Now, unfortunately, this only works if you only use the wired connection in secure places. Say, if you travel and go to an internet cafe that only provided wired ethernet, it all goes down the drain. (Windows therefore nowadays identifies different network connections and simply asks the user whether the network is considered internal or external, and remembers the settings, however, this network recognition might make mistakes!)
If your print server is a stationary machine in a private network with a single network interface, then just assign it to the internal zone and be done with it (which essentially deactivates the entire firewall).