Physical and underlying sub interfaces show different metric values in Performance Management

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

Sub Interfaces on our devices are showing high utilization where the physical port itself shows shows low to no traffic at all. Is this expected or could it relate to a counter issue?

Cause

Different speeds on the different interface items result in different X and Y labels/ratios making the charts look incorrect at first glance.

Environment

All supported Performance Management releases

Resolution

When comparing reports in this scenario it's important to be mindful of the Speed set on the target interface.

One set to 10 MB/s will have lower looking Utilization values than one with a 2.05 MB/s speed.