hp procurve 3400cl misbehaving

[josey]

We have an HP procurve 3400cl (20 port) series switch. Recently we added a new connection to the switch on port 13 and immediately port 1 failed to work ie no traffic comes in or out of port 1 yet when you telnet into the switch everything looks ok. The device we are connecting to port 13 is a router and as soon as we connect it the router connected to port 1 becomes unreachable! We tried connecting it to some other port with the same results. We use MRTG to monitor traffic from the switch and as soon as the router on port 13 is connected the graphs for traffic through port 1 flatten! Amazingly the traffic through port 13 or any other port is not affected it is just port 1. I need some assistance on how to sort this problem out.
Thank you

[Johan Guldmyr]

If the problem does not follow switch port but the device attached I would presume something odd with the device.

Maybe whatever is on port 1 has something weird in its routing table?

What is in port 1?

[josey]

It is a route too, the odd thing is this happened after addition of the second router on to the switch. originally there were nine routers connected to the hp switch but once we put on the new router then port one failed. I checked in the events log and the port to which the new router is connected reports FFI errors but i can not point to why it causes port one only to fail. Thank you for your response

[Johan Guldmyr]

is there something in the configuration that they have 'in common'?

[josey]

The problem was solved. It looks like the second device was doing MAC proxying and somewhere along the connection there was a device picking a MAC address for one of the devices on the connection starting at port one. We deployed a router to connect to port 1 instead of another switch and everything changed. Thanks for your help

[Johan Guldmyr]

Glad to be of some assistance but looks like you got it yourself :-)