Comment 25 for bug 43352

Probably the problem is caused by bugs in the printer's implementation of IPP, so as long as upstream CUPS does not do a work-around in their IPP backend, the best is to use one of the other communication protocol of the printer.

Can everyone of you who reported the problem with printing via IPP run

/usr/lib/cups/backend-available/snmp

Which URI does this program suggest for your printer? If you do not get any answer or only answers from printers which do not have this problem, add the IP of your printer to the command line above.

"snmp" is a network printer auto-detection backend which was introduced with CUPS 1.2. It does not only find the printers but also tries to suggest the most suitable communication protocol (IPP, TCP/Socket, or LPD). During the tine (nearly one year) of the existence of this program many bugs and incompatibilities of the printer's implementations of the network protocols were discovered and now they are taken into account by the "snmp" backend. So it is recommended to use the protocol which "snmp" suggests.

In current Feisty (cupsys >= 1.2.8-0ubuntu3, gnome-cups-manager >= 0.31-3ubuntu3) this backend is activated for use by default. Both the gnome-cups-manager and the web interface of CUPS (http://localhost:631/) make use of "snmp" and show network printers in their lists of detected printers. So users are automatically led to use a protocol which the printer supports correctly.