STP Clinical & Scientific Knowledge 4

Question 1

Which RSTP (802.1w) port state is functionally equivalent to STP's combined Blocking, Listening, and Disabled states?

Accepted Answer

Discarding

Answer

RSTP consolidates STP's Disabled, Blocking, and Listening states into a single Discarding state.

Question 2

What is the primary advantage of MSTP (Multiple Spanning Tree Protocol) over PVST+?

Accepted Answer

Fewer STP instances by mapping multiple VLANs to one instance

Answer

MSTP maps multiple VLANs to a single spanning tree instance, reducing CPU and memory overhead compared to running one instance per VLAN.

Question 3

UplinkFast is a Cisco STP enhancement designed to speed up convergence in which specific scenario?

Accepted Answer

Uplink failure on an access layer switch

Answer

UplinkFast immediately activates a blocked alternate port when the primary uplink to an upstream switch fails.

Question 4

In STP, what port type does the designated port face?

Accepted Answer

Away from the root bridge (downstream)

Answer

Designated ports face downstream segments or end devices and are responsible for forwarding traffic away from the root bridge.

Question 5

What happens to STP topology when two switches have identical Bridge IDs?

Accepted Answer

The switch with the lower MAC address wins

Answer

If bridge priorities are equal, the switch with the numerically lower MAC address is elected root bridge.

(STP) Spanning Tree Protocol Practice Test