The port 631…. is associated with…. IPP, the Internet,, printing protocol Internet,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,, ,,, ,,
What is Port 631 for?…
The port 631/TCP…. is the standard port a IPP and a IPPS, especially with CUPS. The requests for, printing, job tracking and IPP responses go through an HTTP/HTTPS connection on this port. The discovery of, printers is a separate subject: depending on the environment, it can use DNS-SD/mDNS on UDP
To diagnose a print, you must separate discovery from the printer, access to the printer, tactile 631, queue, wait and job processing….
Transport Protocol
TCP
Safety precautions
Should we open this port in the firewall?
Allow the TIPS 631 only between the posts, servers, printing and printers that need it. Do not publish a CUPS or d administration interface, without dedicated protection on the Internet. IPPS can also use 631 with TLS: check the certificate and policies of, access rather than limit yourself to the port number….
How do I check this port?
Test the server or the printer for HTTP/IPP. On a CUPS server,…. lpstat -v helps to identify the URI used by the printer and…. ss -lntp helps verify the CUPS printer configuration….
- Identify the URI and the print queue actually used….
- Test access to the target…
- Control the file status, format/pilot and logs of the spooler…
- If the printer is not discovered, process separately DNS-SD/mDNS and the local network….
FAQ — port 631 / IPP….
Does IPP use TITCH or UDP on port 631?….
IPP uses TITLE on port 631. Discovery mechanisms may use other protocols, e.g. mDNS on UDP 5353, but this is not IPP transport….
Why is port 631 answering, but the document is not coming out?….
Connectivity can be correct while the file is stopped, the job is rejected, the format is incompatible or the spooler encounters an error….
Does IPPS use another port?….
IPP and IPPS can both use port 631; the difference is the TLS protection of the connection…