Spanning Tree Protocol 2
Terms
undefined, object
copy deck
- What do bridges and switches running STP use to exchange information?
- Bridge Protocol Data Units (BPDU's)
- What do BPDU's use to send configuration information?
- multicast frames with the bridge ID of each device
- What is a bridge ID used for?
- determining the root bridge and root port
- How long is a bridge ID?
- 8 bytes, including the device's priority and MAC address
- What is the default device priority?
- 32768
- How is the root bridge chosen?
- by highest priority; lower MAC address wins ties
- What are the four spanning-tree port states?
- blocking, listening, learning, and forwarding
- How does a port behave when in blocking mode?
- it won't forward frames, but listens to BPDU's
- What spanning-tree port mode is the default on startup?
- blocking
- How does a port behave when in listening mode?
- it listens to BPDU's to ensure no loops will be created before forwarding
- How does a port behave when in learning mode?
- it learns MAC addresses and builds a filter table, but does not forward frames
- When are listening and learning states primarily used?
- When a topology change occurs
- When do ports use listening mode?
- When a blocked port determines that it should now be the designated port; it listens to determine that no loops will be created
- At what point does convergence begin?
- when all bridges and switches have trasitioned to forwarding or blocking states
- Is data forwarded during convergence?
- no
- Why is convergence important?
- to ensure all devices have the same database
- How long does convergence take?
- about 50 seconds
- What is a forward delay?
- the time necessary to transition a port from listening to learning, or from learning to forwarding