MSTP controllers go offline when changing the MaxMaster value in the Automation Server from it's default of 127.

Issue

MSTP controllers  go offline when changing the MaxMaster value in the Automation Server from it's default of 127.

Product Line

Andover Continuum, TAC I/A Series, SmartStruxure Solution, SmartStruxure Lite

Environment

Automation Server

MSTP Controllers

Cause

The maxmaster value is being set lower than some or all of the MSTP controllers on the network. 

Resolution

The value for maxmaster needs to be at least one greater than the highest addressed MSTP node id. If your last node is MAC id=54 then your maxmaster will need to be set to 55 or higher.