snmpcollector CPU metric family discovery on Cisco 3850 devices (and potentially others)

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)

Issue/Introduction

The snmpcollector does not successfully discover CPU metric families on Cisco 3850 devices.

Environment

Release: Any Unified Infrastructure Management (UIM) version 

Component: snmpcollector probe

device make/model - Cisco 3850

Cause

The target device cannot deliver a large batch of OID values all at once.

Resolution

Open the snmpcollector raw configuration mode and navigate to the 'settings' folder.

Add a key called 'MAX_BATCH' and set it's value to a low number.  20 is the default, so perhaps test with 5 and adjust up or down as necessary.

Additional Information

At time of this writing the Cisco 3850 is not on the supported device list in spite of having the same MIB tree as supported devices.

1. This same situation could occur for many – usually older- devices, not just the 3850 device.
2. The tuning parameters to handle such devices are MAX_BATCH (default 20), "snmpretries" (default 2), and "snmptimeout" (default 2000 milliseconds). We recommend that the overall performance of the system (discovery and polling) should be observed carefully when changing these parameters.