CIDR routes on Sonicwall NSA 3500 appear incorrectly in NPM

Version 1

    Hello, I spent some time on the following issue so wanted to pass this along in case someone else saw weird stuff from their Sonicwall device. The attached shows the Routing Table where the 192.168.10.0 route is not /24, but is reported as such.

     

    Symptoms

     

    In the resource "Routing Table", the CIDR may not be accurate for the Sonicwall NSA 3500. For example, the CIDR may always be reported as 24 regardless of variable length subnet masking (VLSM.)

     

    Cause

     

    While Sonicwall devices may respond to standards based MIBs, they only support custom MIBs published through www.mysonicwall.com . Specifically, the Sonicwall NSA 3500 may provide incorrect responses to requests for OID 1.3.6.1.2.1.4.21.1.11 (ipRouteMask)

     

    Workaround

     

    Remove the resource "Routing Table" from NPM for the Sonicwall NSA 3500.