IPP backend fails on cups 1.2.x

[Ioannis Ramfos]

I have a USR9108 router which has a printer server (usb port) and an HP Deskjet 5652 printer connected on that. The router runs an ipp server.

When using cups 1.1.23 on a Slackware system, printing is working correctly. The printer turns on automatically and printing begins.

In cups 1.2.x (tried 1.2.4, 1.2.7 and 1.3, Ubuntu and Slackware systems) printing fails and the message /usr/lib/cups/backend/ipp failed appears on the web interface and the job is paused. The printer does not turn on. Occasionally the ethernet led on the router blinks repeatedly as it tries to send data to the printer unsuccessfully (and may lead to router unresponsiveness).

When connected locally, the printer works correctly with cups 1.2.x.