Hello All, Still chasing, but a slightly different tack. When I set it up, it sets to "socket://192.168.0.215" which research shows as the HP JetDirect protocol. There are comments in the CUPS documentation that the vendors implement the IPP (Internet Printing Protocol) with deficiencies that mean it is better to use other protocols. Does anyone here have any information to contribute? I do not want to run Windows, but will set up a Windows box if necessary and sniff the packets to see what is going on. That will take undue time and effort at the moment, but would provide real answers. If anyone can find answers where someone has done any of that, I would very much appreciate information. I would still appreciate a bit of a network primer about the netmask and the like. I also need to "discover" the ip address of the switch I have, it does not respond at what I have found on the net as the default ip address. Regards, Mark Trickett