Re: NETMON causing high SNMP Util on router

I've seen the same problem at several of my customers sites.  How large are
your routing tables? I've seen the SNMP process run the cpu really high when
netmon is trying to get the routing table.  The following lines in your
cisco configs will prevent netmon from getting the routing table (ip.21) via
snmp.  I haven't really seen any negative effects to blocking the routing
table, but their might be some.

        snmp-server view demandpoll mib-2 included
        snmp-server view demandpoll ip.21 excluded
        snmp-server view demandpoll private included
        snmp-server community whatever RW
        snmp-server community public view demandpoll RO

You can also use a sniffer to help determine exactly what is happening.
That is how we initially solved the problem.


Marc Russo (mrusso AT al.iisl DOT com)
International Integrated Solutions, LTD



-----Original Message-----
From: Sean Davidson [mailto:sean.davidson AT MAIL.PUBLIX DOT COM]
Sent: Wednesday, October 13, 1999 4:01 PM
To: NV-L AT UCSBVM.ucsb DOT edu
Subject: NETMON causing high SNMP Util on router


Having a problem where the IP SNMP process on a Cisco 7507 is using a lot of
CPU. CPU on the router will go to 99% for 20 to 30 min. I look at the
processes on the
router and the IP SNMP process is getting 70% of the CPU. I stop netmon and
CPU drops to 25%. Restart netmon and I'm fine for a while, but at some
point, the same problem happens and the process repeats.

I'm running the following:

AIX v4.2.1
Tivoli 3.6.1
NetView/6000 v5.1.1

For what it's worth, the router is a Cisco 7507 w/ RSP2. Because the SNMP
process and not the IP forwarding or any of the processes related to
forwarding data, the traffic has to be SNMP destined for this router. I've
tried turning netmon tracing on for SNMP requests (tracemask 4), but I've
got 30,000 objects in my database and this creates quite a bit of ouput, so
I can't tell what's going on. Is there a better way to see what's happening?

__________________________
Thanks,
Sean Davidson

Sr. Network Systems Engineer
Publix Super Markets, Inc.
P.O. Box 32015
Lakeland, Fl. 33802-2015
Email - sean.davidson AT publix DOT com
Voice - (863) 686-8754 x6889
Fax - (863)616-5895