SNMP and CPU

martin.belisle · ‎01-07-2010

Anyone can tell me in general how much polling interfaces data with SNMP will affect the CPU?

For example, I have a 4507E and I'm polling in/out bits/s and errors every 5 minutes for 6 PO interfaces. I don't see any impact at all on CPU.

Now there are 120 servers connecting to it. Is it reasonable to think I could poll the switch for every interfaces? Would it make a difference or polling is polling no matter how many interfaces.

thank you

Joe Clarke · ‎01-07-2010

Polling is definitely not polling. The more objects being polled, the more impact that will have on the CPU. SNMP is a low priority process, so it should relinquish CPU if a higher priority process needs it, but if not, it will run as hot as it needs to. If you are going to do a lot of polling, limit the number of request packets. Use GETBULK requests to pull down large numbers of objects at once.