Cisco interface input errors, but no CRC, frame counts, etc??

Question

I am getting input errors on a GigabitEthernet port. The strange part is that only the input errors field is incrementing, and not any of the other fields. See below for example:

5 minute input rate 74000 bits/sec, 10 packets/sec
5 minute output rate 10000 bits/sec, 17 packets/sec
267055 packets input, 223245611 bytes, 0 no buffer
Received 9 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
41534 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
803512 packets output, 127314215 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out

Answer 1

Well I'd like to see more output from the device, like a full "show run" or "write t" and a "show int".



With so little to go on however my first guess would be a frame type mismatch of some sort, or even a speed negoiation issue.



For problems like this its best to include as much output from the device as you can, as well as as much data about it, i.e whats it doing, whats it connected to, whats working or not working, etc. We can write some pretty long and detailed responses but it helps if the questioner writes as much detail as they can about the problem.



Additionally you probably want to use the "clear counters" command and see if the input errors are still coming in. Its possible these errors are old and were caused by a temporarily disconnected cable, etc. Before you go troubleshooting the problem further, clear the counters and see if you even have a problem.



Hope that helps.



Layer9

Layer9Security.com

Answer 2

i had the same problem, high iput errors with 0 crc errors, i first suspected a duplex problem but i was wrong. it turns out the tunnels going through the interface had misconfigured mtu. i just lowered the mtu to 1400, also added the following command:

ip tcp adjust-mss 1360

maybe

tunnel path-mtu-discovery

also helped.

Answer 3

Bad cable replace it.