Interface CRC and Input Errors

[jmcmasters]

I have been looking for awhile but what would be thresholds for input errors and CRC errors for an interface. I am looking for something in our status monitoring systems. I would imagine no errors is good. But was not certain how many per hour per minute for the number of packets is acceptable.

-Jeremy

[Giuseppe Larosa]

Hello Jeremy,

there are no absolute numbers but just relative figures: the packet error rate is what determines if errors are too much or acceptable.

An error rate below 0.1 percent is usually acceptable if the biggest part of traffic is TCP with retramission built-in capabilities.

You need to compare the total number of input errors with the total number of input packets:

input errors / (input errors + input packets)

There are for example some WAN links that are near tech reach limits that are never error-free.

Hope to help

Giuseppe

[deyadav]

Hi Jeremy,

As far as I know there is no such limit, now its upto you how much you want to specify for your monitoring tool.

Input errors are cumulative of CRC, Frames, Overruns, Ignored, Runts, Giants and throttles.

CRC, Frames, Overruns and Ignored are Layer 1 issues, so could be plenty at any given point of time incase of a bad cable, NIC or interface or due to bursty traffic rate.

This links gives understanding to the counters

http://cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a008015bfd6.shtml