underruns and output errors

[spidermanfan]

Hello all,
We have a Cisco 7200 and on one of the ethernet ports we are seeing an extreme amount of underruns and output errors.
I need to get a better understanding of these to help me trouble shoot them better. What are excatley are underruns?

Thanks

 

[jgercken]

The buffer can't keep up speed with the demand of the tx interface. It empties and causes runt frames.

Cisco's explaination:
"Each time that a transmitter is running faster than a routing device can handle, the routing device reports an underrun."

reference: Solving Ethernet Problems

http://www.cisco.com/univercd/cc/td/doc/product/voice/ics7750/tblshoot/tsether.pdf