IMC snmp polling causes high CPU usage on Enterasys/ExtereNetworks S4.

[rddr]

Hi,

I am using HP IMC 7.3. When I add Enterasys S4 backbone switch to IMC, cpu usage climbs to %99 on S4. I look which process eats cpu on S4 and see it is snmp process. When I look at snmp counters on S4 I see there is about 1k snmp packets per second. When I stop IMC services cpu usage and snmp counters returns to normal.

So why IMC is hammering S4 with thousand of snmp queries per second? Any idea how to solve this?

 Edit: I just run wireshark and see that IMC is sending bulk requests about these oids non-stop. So the problem seems these requests:

1.3.6.1.2.1.17.7.1.4.2.1.1 (dot1qVlanTimeMark)
1.3.6.1.2.1.17.7.1.4.2.1.2 (dot1qVlanIndex)
1.3.6.1.2.1.17.7.1.4.2.1.3 (dot1qVlanFdbId)
1.3.6.1.2.1.17.7.1.4.2.1.4 (dot1qVlanCurrentEgressPorts)
1.3.6.1.2.1.17.7.1.4.2.1.5 (dot1qVlanCurrentUntaggedPorts)
1.3.6.1.2.1.17.7.1.4.2.1.6 (dot1qVlanStatus)
1.3.6.1.2.1.17.7.1.4.2.1.7 (dot1qVlanCreationTime)

Can I stop these requests about vlans or at least make IMC more gentle on the switch about this topology polling?

Thanks,

Rahman

[rddr · Accepted solution]

Hi,

I think I solved the problem. Here is the solution for reference: https://extremeportal.force.com/ExtrArticleDetail?n=000005727&q=snmp%20timefilter

Cause

MIB Tool querying the switch doesn’t understand a ‘timefilter’ mib RFC2021

Resolution

The following command is a workaround for the issue

set snmp timefilter break

Regards,

Rahamn