LPR printing across IPSEC L2L tunnel problem.
Posted on 2008-10-30
I have an odd problem that I can't seem to figure out. I have a Site-to-Site IPSec VPN tunnel setup between two Cisco 1841 routers. On the remote end there exists a windowsXP machine, an HP LaserJet printer, and a Mitel IP Phone. On the local end, there exists a unix based lpr print server with a queue that points to the IP of the remote printer, on port 9100.
The IP phone works, everything pings, the connectivity is good, and the latency end-to-end is less than 30ms with little jitter. From the Unix printer server on the local end, I can ping the printer, and I can telnet to the printer on ports 23 and 9100. The response on the ports of the printer does not lag nor hang.
The problem is that the printer won't print jobs sent to it from the LPR print server on the Unix server. The jobs just site in the print server queue, the printer does not show the blink light to signify that it is spooling. If I telnet to port 9100 on the printer, from the the printer server, and type some text, that prints.
A packet sniffer sitting on both ends shows packets leaving the printer server, the first 3 or 4 of which make it end to end in both directions, but the larger packets (1500 each) from the printer server don't make it. I set fragmentation on the crypto-map but it doesn't change anything. I set the mtu on the interfaces along the leg to as little 1000 (from 1500) and a few more packets get through, but the net result is still exactly the same.
Any ideas to fix this would be helpful.