High cpu in monitoring because of SnmpSubagent andf SnmpMaster processes

[Frank_Veen]

Hi all,

Can anybody help explain why the snmpMaster and snmpSubagent processes are using a lot of cpu during snmp polls? Maybe misconfiguration?

Running image is 16.1.3.6-patch1-9

In our monitoring we see that every few minutes the cpu utilisation of one of our X440's is abnormal high. Our monitoring server uses snmp polls every minute to get the switch cpu utilization (among other things).

This is happening when there is almost no traffic even, for example during nights. See the image below the cpu utilization every few minutes around 40%:

Now the top command on the switch shows more info, clearly the SnmpMaster and SnmpSubagent are using a lot of CPU during the poll:

Kind regards,

Frank

[Tripathy__Priya]

Looking at the above output i could say "bcmlink.0" and "bcmlink.1" can show even maximum 20-22% each while using default config. The cause which i would feel here is the use of default config in the setup.

[Frank_Veen]

Ok I will add the deny all rule to see if I get any logging.

Another / maybe linked "problem", I see that two processes are using +-10% cpu all the time bcmLINK.0 and bcmLINK.1. Can anybody tell me if this is normal behaviour? I can't find any documentation about these processes.
*Edit: I did find docu :):
https://gtacknowledge.extremenetworks.com/articles/Q_A/What-is-the-functional-responsibility-of-bcmL...

[StephenW]

Yes, You do need a deny all ACL.

[StephenW]

Make sure SNMPv1 is not being used. SNMPv1 doesn't have GetBulkRequest like V2 whitch can cause the CPU to go high when requesting a lot of data.

[Roy_Noh]

There's an article on GTAC knowledge base explains similar issue.

https://gtacknowledge.extremenetworks.com/articles/Solution/snmpMaster-process-runs-high/

Basically, the CPU utilization goes high when there's an excessive number of snmp request.
So I think you'd better check the numbers of snmp request first.

And if so, the article suggest a solution for that with installing access profile.

I hope this might be helpful.