29.7.12 Setting the Fault Monitoring Time for Rings with Stacked Nodes

The stack load balances communication between member switches when multiple stack links are configured. If a stack link failure occurs, the switch is made so that the stack link is not allocated to the failed stack link, but communication stops temporarily until the switch is completed.

If the failure monitoring time (health-check holdtime) of the master node is shorter than the time for the stack link switching to complete, the health check frame is discarded. Therefore, the master node misdetects a ring failure and switches the route. which might cause loops to occur. For this reason, when a ring contains a stacked node, set the failure monitoring time of the master node to 1 second or longer.