High Frame errors on switch / trunk

[MagellanTX]

Hello,

I am getting a large number of frame input errors on my trunk port. I have a 3548 connected to a 3640. Even ping packets generate errors. I have tried different cables and different ports. The router has 0 errors, they all appear on the switch.

I have no clue on how to troubleshoot this so any ideas would be great.

Thanks!

[Prashanth Krishnappa]

Is this an ISL trunk? If so, it is due to the following hardware limitation with ISL trunking on this platform

http://www.cisco.com/cgi-bin/bugtool/onebug.pl?bugid=CSCdr22809

[Kevin Dorrell]

A framing error ocurs when the number of bits in a received frame is not an exact multiple of 8. So where does this leave us practically?

I would guess that it is more likely the transmitter at fault than the receiver, althought thoeretically both are possible. You say you have tried different ports - I presume you mean switch ports. Have you tried different interfaces on the router?

What I am saying is that the most likely scenario is that the transmitter in router is a fault, and the switch is counting the badly framed frames it receives. (The errors at the router are zero beceuse it does not know it is transmiting faulty frames.)

Kevin Dorrell

Luxembourg

[MagellanTX]

Thanks Kevin you pointed me in the right direction. The problem was that the FA0/0 was set to half-duplex. I never even look at the main interface itself, I was just concerned that the sub-interfaces were correct. Once I changed it everything started working.

Thanks again!

[Kevin Dorrell]

OK, I am glad it is working now. That's interesting, because maybe I misunderstood what sort of errors they were. From your original posting, I had understood they were framing errors, but now I read it more carefully I see you wrote "frame input errors". So I bet they were actually runts and alignment errors. Runts are an instant clue to a duplex mismatch.

All's well that ends well.

Kevin Dorrell

Luxembourg