Which three components are combined to form a bridge ID?port IDbridge priorityIP addressMAC addressextended system IDcost

The three components that are combined to form a Bridge ID in a Spanning Tree Protocol (STP) environment are:

1. Bridge Priority: This is a value that determines the priority of a bridge in a network. The lower the bridge priority, the higher the chance that the bridge will be selected as the root bridge.

2. MAC Address: This is the physical address of the bridge. It is used as a tie-breaker if two bridges have the same priority.

3. Extended System ID: This is essentially the VLAN ID. It was added to the Bridge ID structure to support Per-VLAN Spanning Tree Plus (PVST+).

So, the Bridge ID is composed of the Bridge Priority, MAC Address, and Extended System ID.