I've never seen anything like this before and I'm completely baffled at this point.
We have a flat network with about 200 devices including workstations, servers and printers. Everything was working fine this morning, then all of a sudden we started getting complaints about people not being able to print. We traced it down to 3 printers, all different models of HP laserjets. They all exibit the same symptoms.
1. A few minutes after plugging in a network cable, the on-device interface locks up completley
2. The printers are not able to completely reboot while a network cable is plugged in, they get stuck at initalizing
3. Running a continuous ping gives about a 50% to 60% packet loss. Usually with destination not found, but sometimes timed out
4. Isolating the printer to it's own network with a small switch and a laptop works fine, the laptop can ping the printer and print normally. ie, while not plugged into the rest of the LAN
5. If I plug the laptop into the same cable and port the switch was using on the LAN, the laptop works fine and has no issues.
Network setting have all been varified on the printers. Tracert to each printer, when it's able to succeed, doesn't show any routing going on. There are no VLANS in play. Other printers of the same model are working fine on the same switches and IP range. The print servers the printers are set up on seem to be working fine. I checked to make sure there are no MAC duplications. The only thing the 3 printers have in common is that they are in the same building, but like I said, there are other printers in this same building that are not having problems.
I'm stummped. This has to be a networking problem, right? Ping only deals with layers 1 - 3. What am I missing or can anyone think of anything else to try?
Tomorrow morning I'm going to shutdown both print servers to make sure nothing odd is going on there. The only thing I can think to try after that is to hook up a switch with port mirroring and look at the traffic one of the printers is getting and sending. Maybe something will stand out.
