show interface counters wrap around?

[steve.dutky]

Do the show interface counters wrap around at 2^32-1?

[yjdabear]

AFAIK, the "show interface" counters are not based on the equivalent SNMP MIB values. The formers are cleared by reboots or by manual actions. The latters wrap around depending on what size of counters they are (e.g. The one you quoted is for 32-bit MIB counters.) If "show interface" counters wrap around automatically like MIB values, we'd see far fewer outputs of: Last clearing of "show interface" counters never.

[Marvin Rhoads]

Further, the following Cisco document:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_q_and_a_item09186a00800b69ac.shtml

contrasts the output from "sh int" with that from an snmp query.

Hope this helps. Please rate helpful posts.

[steve.dutky]

Thank you both for the helpful information for the snmp ifMIB.

Specifically, I need to find out when the show interface counters for input and output packets overflow.

These two apparently do not correspond to any ifMIB variables.

Thanks again.