BPDUs (Bridge Protocol data Unit) introduction

BPDUs are message frames exchanged between switches running STP. Each BPDU contains a BID that identifies the switch that sent the BPDU. The BID contains the priority value, the MAC address of the sender switch, and an optional extended system ID. The size of the BID value is determined by the three fields together.

BPDU Multicast Address: 01-80-c2-00-00-00

There are 2 types of BPDUs:

1. Configuring bpdu– for STP calculations

2. Topology change notification (TCN) bpdu– used to advertise changes in the network topology

BPDUs (Bridge Protocol data Unit) introduction