1720 possible failed ethernet port?

[Tallon]

Ok, i've been pulling my hair out for two days before a friend referred me to these forums. I hope you all can help me



We have 2 branches connected via a 56K privateline, with a Cisco 1720 on either end (56K CSU/DSU WICs). Suddenly a few days ago Or Orlando branch (I'm in Miami) lost connection to our AS/400 server in Miami. This wa sdiscovered on a Minday morning, so it could've been over the weekend. Here's the deal:


With nothing plugged into the router in Orlando, I can ping it great. 56 ms dead on all day long. However, as soon as we plug a switch or a PC into the 10/100 ethernet port, the pings jump to 2000/4000 ms or higher, with about 20% packet loss. Unplug the switch, and after a minute or so of high pings they lower themselves back down to normal. I've tried swapping cables, tried a new switch, tried several PCs, all with no success. Could the ethernet port on the router be bad, or is there something else I'm overlooking?



Thanks guys


Carlos "Tallon" Moll

 

[netmediasystems]

interesting problem...ive had problems before if fast-switching was enabled on the eth port. also, check the duplexing setting. do a sh int fasteth0 from router#. also if cisco express forwarding is enabled, that has a history of causing problems. and one other problem that i can think of, at least in a situation ive encounter was no ip mroute-cache. although this was more related to a VPN situation if i can remember correctly, try enabling that on the interface. you could also post your sh int fasteth0 on this tread...that would help.

brian