
CISCO – Spanning Tree Enhancements
Loop Guard This feature prevents a port from erroneously transitioning from blocking state to forwarding when the port stops receiving BPDUs. The port is marked as being in loop-inconsistent state. In this state, the port does not forward packets. The possible values are Enable or Disable. TCN Guard Enabling the TCN Guard feature restricts the port from propagating any topology change information received through that port. This means that even if a port receives a BPDU with the topology change flag set to true, the port will not flush its MAC address table and send out a BPDU with a…