I have a cisco 1720 router that has been showing a very large amount of
interface output errors (100's of thousands), along with that, there seems
to be a problem with underruns and input errors, though not as bad. 2 of
the 3 interface's are also having a problem with excessive collisions.
Would this most likely be a physical interface problem, or router
(hardware/software) problem. I have a feeling it might be a problem with
autonegotiation, but am unsure.