Interface errors

Hi All,

I'd assume this router has a faulty ethernet interface, what does experts say?

Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 81000 bits/sec, 71 packets/sec 5 minute output rate 1000 bits/sec, 2 packets/sec 250630345 packets input, 907360465 bytes, 6261 no buffer Received 230027406 broadcasts, 0 runts, 876 giants, 1431138 throttles 669130 input errors, 218 CRC, 668036 frame, 0 overrun, 0 ignored, 0 abort 0 input packets with dribble condition detected 48160333 packets output, 1326134205 bytes, 0 underruns 685 output errors, 846589 collisions, 2 interface resets 0 babbles, 0 late collision, 90025 deferred 1 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out

Thanks, Alex

Not necessarily faulty at all.

The most critical thing is to establish when these various event counters recorded the events. They may be historic and of no current interest.

Clear counters

Start again.

If the interesting counters record anything please post the whole of the "sh int" output and the model of the router "sh ver". Some idea of how busy the interface is supposed to be would be good.

sh int x sh ver sh interface switching sh interface stats sh run int x

Assuming that the config on the interface or any connected device has not been changed then:-

No drops this is good.

Low utilisation at present.

A few no buffer 6 in 250,000 or 1 in 50000. You may be able to fix this with buffer tuning.

0.5% throttles. This indicates that the router has been overwhelmed with traffic. You need to make sure that you are "Fast Switching" i.e. one of Fast/CEF/NetFlow If you are then you need to reduce the traffic or get a biger router.

These may be OK or they may indicate that you have a duplex missmatch.

Collisions and deferred are OK. A few output errors. It doesn't say here what they are.

Basically if this is a corporate backbone there is an issue but if it is for a bit of internet access then it will be OK as it is but could be improved.

The biggest problem seems to be the routers basic load capacity. I would retain the Half Duplex to try to save it from even more traffic.

If the router is a small one and the link is 100M you could reduce it to 10M which may save the router from being overwhelmed.

If you want advice on buffer tuning post sh mem (the first few lines only) and sh buff.