We have a number of printers that say communication failed either on lpr or raw, restarting printer never fixes it.

to fix we've been going in and switching the printer from lpr to raw or vice versa and then it works for a while(days, weeks in some cases).

So far it does seem like its all external jet directs, firmware has been upgraded on some of them but the problem still persists regardless.

Anyone else have this issue?