Finisar Surveyor manual Unstable MST, Rate of change of Topology=10

Surveyor

User’s Guide

Unstable MST

Counter

The Unstable MST counter increments when a change in the number of MST topology changes per second exceeds a threshold. The default threshold is a delta of 5 topology changes per second; however, this value can be changed from the Expert Thresholds tab in the Configuration → Module → Settings... menu. A count of all Unstable MST events displays in the Overview counters of Expert View. A threshold for this counter can be set in Expert Alarms.

MST topology changes are topology changes required to support IEEE 802.1d (Minimum Spanning Tree). Excessive topology changes infer that the Minimum Spanning Tree (MST) is unstable.

Expert Symptom

Unstable MST events are automatically logged as expert symptoms. The Symptom Summary field provides information about the rate of change for the MST topology. For example:

Rate of change of Topology=10

Diagnostic Details

__________________________________________________________________

Problem Description:

The threshold for the number of IEEE 802.1D packets with topology change bit has been exceeded for this segment. The Spanning tree may be unstable.

__________________________________________________________________

Probable Cause(s):

1.There may be too many configuration changes for the bridge/switch.

2.There may be a temporary loss of connectivity.

__________________________________________________________________

Recommended Action(s):

1. Identify the device causing this message and fix it.

10-100