Ignored errors on Ethernet

[oleg]

Hi,

I have a 2611 with Ethernet/10M/full-duplex connected to catalist 1900 10M/full-duplex. I noticed that ignored errors are detected on the Ethernet router interface and their rate increased when traffic is higher. I tried to change cable, ports and duplex-mode without success.

Any ideas what could cause these errors?

Thanks

[MickPhelps]

Ignores usually occur when packets are comming in to the router's interface faster than the interface can move them from its hardware buffers into the router's memory.

Are you getting any other errors? Is it possible you have a layer-2 loop or broadcast storms?

From CCO: ignored

Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.

Mick.

[oleg]

No other errors:

Received 1121 broadcasts, 0 runts, 0 giants, 0 throttles

12683 input errors, 0 CRC, 0 frame, 0 overrun, 12683 ignored

The broadcast counter is not high - does it prove that there is no broadcast storm. Also I'm sure we don't have a loop.

Is there any advanced debug or other staff that can help to find the source of errors?

[MickPhelps]

I would span the switch port and use a sniffer to figure out what packets are being sent to the router in such high volume.

Clear the counters and watch them until the Ignores start increasing again then start the sniffer. Check the counters again and if they Ignores have increased, stop the sniffer and find out who your "top talkers" are.

Mick.