Extended Monitoring Guide

5. Limit SNMP Requests for Cisco PIX, ASA and FWSM Devices
Prev Chapter 23. Cisco Devices Next

5. Limit SNMP Requests for Cisco PIX, ASA and FWSM Devices

Zenoss tends to run into problems querying Cisco PIX, ASA and FWSM devices using SNMP. This is because by default Zenoss tries to fit 40 requests into a single SNMP packet when using SNMP v2c to improve performance and reduce network and processing overhead on Zenoss and the monitored device.

Common symptoms of this problem include:

  • DEBUG level /Perf/Snmp events with a summary field of Error reading value for "???"

  • Missing performance graphs.

  • Errors like the following in the Cisco device's log:

    incoming SNMP request (? bytes) from IP address ?.?.?.? Port ? Interface
    "inside" exceeds data buffer size, discarding this SNMP request.

Set the zMaxOIDPerRequest property to reduce the number of requests per SNMP packet to four (4) for all of your Cisco ASA, PIX and FWSM devices.

Prev Up Next
4. Forwarding Syslog Messages to Zenoss Home 6. Daemons