STP STP Fundamentals 2

Question 1

What is a designated port in STP?

Accepted Answer

A port on each segment that provides the best path to the root bridge and forwards traffic

Answer

Each network segment has one designated port that forwards traffic, determined by having the lowest cost path to the root bridge.

Question 2

What is an STP root port?

Accepted Answer

The port on each non-root switch that has the lowest cost path to the root bridge

Answer

Each non-root switch selects one root port, which is the port with the best path (lowest cost) to the root bridge.

Question 3

What causes an STP topology change?

Accepted Answer

A port transitioning to or from the forwarding state

Answer

Topology changes occur when ports change state, triggering the network to update its forwarding information.

Question 4

What is the STP max age timer?

Accepted Answer

The maximum time a switch stores BPDU information before discarding it, default 20 seconds

Answer

If a switch does not receive a BPDU within the max age period, it assumes a topology change and begins recalculating.

Question 5

What is the convergence time for 802.1D STP?

Accepted Answer

30 to 50 seconds typically

Answer

Traditional 802.1D STP can take 30-50 seconds to converge after a topology change as ports transition through states.

(STP) Spanning Tree Protocol Practice Test