Capturing interface errors with SNMP

[7tsommer]

Is there a proper way to query a router's interface for input errors? The only OID I could find for this was .1.3.6.1.2.1.2.2.1.14.n (with "n" being the interface to query), but when I do a "show interface..." the input errors don't match the number of the SNMP query. What, specifically, does this OID return? Is there another set of OIDs that will specifically grab the input errors on a serial interface, as shown in the "show interface..." command?

Thanks,

Tyson

[Kevin Dorrell]

The official definition of that OID, ifInErrors, can be found in RFC3635 , at the top of page 10:

http://www.ietf.org/rfc/rfc3635.txt?number=3635

The sum for this interface of dot3StatsAlignmentErrors, dot3StatsFCSErrors, dot3StatsFrameTooLongs, and dot3StatsInternalMacReceiveErrors.

Normally, I have found a pretty good correspondence between what shows on the show int and what I can see in the MIB. One thing to check is that you have got the interface instance correct - it is quite easy to be out by one, and be reading an entirely different interface. Do the other counters, ifInPackets, ifOutPackets, etc, correspond?

Do you know about the SNMP Object Navigator tool?

http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en

Hope this helps.

Kevin Dorrell

Luxembourg

[7tsommer]

OK I see what was happening. Apparently this MIB doesn't clear its value when you issue a "clear counters interface..." on the interface you're querying, so the numbers can look drastically different. Still can be useful for detecting incrementing errors during any given interval, though.

Is there a way to clear these snmp error counters? Or do they reset only upon a router reload?