Jan 21, 2010

c-BPDU(configuration BPDU) vs tcn-BPDU(topology change BPDU)

There are two types of BPDU's: configuration BPDU's (c-BPDU) and topology change BPDU's (tcn-BPDU).

Designated Bridges generate c-BPDU's. Root Ports and BLocked Ports listen for c-BPDU's.

c-BPDU's originate from the root bridge and flow out towards the edge of the spanning tree, c-BPDU's are re-generated at every bridging device that receives them.

tcn-BPDU's originate from root ports and flow towards the Root Bridge.

c-BPDU's are the heartbeat of the Spanning Tree,
tcn-BPDU's are the heart attack of the spanning tree.
Post a Comment