Bridge Assurance Must Be Enabled At The Remotely Connected Interface. Optional SpanningTree Features SMEnode Here, Network with Normal STP Topology shows a normal STP topology, and Network Loop Due to a Malfunctioning Switch demonstrates a potential network problem when the device fails (brain dead) and Bridge Assurance is not enabled on the network If the device on one side of the link has Bridge Assurance enabled and the device on the other side either does not support Bridge Assurance or does not have this feature enabled, the connecting port is blocked.
Spanning Tree Bridge Assurance from networklessons.com
The implementation must detect unidirectional links due to one-way traffic twisted-pair links Bridge assurance must be enabled between SW2 and SW3
Spanning Tree Bridge Assurance
The Layer 2 domain must be protected from superior BPDUs that arrive from external switches. With Bridge Assurance enabled, BPDUs are sent out on all operational network ports, including alternate and backup ports, for each hello time period. And both ends of the link must have Bridge Assurance enabled.
Rockhopper VPN (REMOTE ACCESS EXAMPLE). Finally, both ends of the link must have Bridge Assurance enabled After the network port receives a BPDU again, the port begins its normal spanning tree.
Remote bridge monitoring Roads and Bridges. One of issues of CCIE is Bridge Assurance in legacy STP If a Bridge Assurance-enabled network port does not receive any BPDU for a configurable period of time, the interface moves into the blocking state