CCNAv2 5-6 EXAM Practice Questions

What additional information is contained in the 12-bit extended system ID of a BPDU?

• MAC address

• VLAN ID

• IP address

• port ID

During the implementation of Spanning Tree Protocol, all switches are rebooted by the network administrator. What is the first step of the spanning-tree election process?

• Each switch with a lower root ID than its neighbor will not send BPDUs.

• All the switches send out BPDUs advertising themselves as the root bridge.

• Each switch determines the best path to forward traffic.

• Each switch determines what port to block to prevent a loop from occurring.

Which STP port role is adopted by a switch port if there is no other port with a lower cost to the root bridge?

• designated port

• root port

• alternate

• disabled port

Answer explanation

Explanation: The root port is the port with the lowest cost to reach the root bridge.

Which two concepts relate to a switch port that is intended to have only end devices attached and intended never to be used to connect to another switch? (Choose two.)

• bridge ID

• edge port

• extended system ID

• PortFast

• PVST+

Which three components are combined to form a bridge ID?

• extended system ID

• cost

• IP address

• bridge priority

• MAC address

Answer explanation

Explanation: The three components that are combined to form a bridge ID are bridge priority, extended system ID, and MAC address.

1a) Which description is the correct match for the Rapid PVST+ protocol?

• the legacy standard for STP that runs all VLANs in a single spanning-tree instance

• a protocol that allows multiple VLANs to run in a single spanning-tree instance

• a Cisco enhancement of RSTP to provide a spanning-tree instance for each VLAN

• an evolution of STP that provides faster convergence

1b) Which description is the correct match for the STP protocol?

• the legacy standard for STP that runs all VLANs in a single spanning-tree instance

• a protocol that allows multiple VLANs to run in a single spanning-tree instance

• a Cisco enhancement of RSTP to provide a spanning-tree instance for each VLAN

• an evolution of STP that provides faster convergence

1c) Which description is the correct match for the MSTP protocol?

• the legacy standard for STP that runs all VLANs in a single spanning-tree instance

• a protocol that allows multiple VLANs to run in a single spanning-tree instance

• a Cisco enhancement of RSTP to provide a spanning-tree instance for each VLAN

• an evolution of STP that provides faster convergence

In which two port states does a switch learn MAC addresses and process BPDUs in a PVST network? (Choose two)

• disabled

• forwarding

• blocking

• listening

• learning

Answer explanation

Explanation: Switches learn MAC addresses at the learning and forwarding port states. They receive and process BPDUs at the blocking, listening, learning, and forwarding port states.

If no bridge priority is configured in PVST, which criteria is considered when electing the root bridge?

• lowest MAC address

• lowest IP address

• highest IP address

• highest MAC address

Answer explanation

Explanation: Only one switch can be the root bridge for a VLAN. The root bridge is the switch with the lowest BID. The BID is determined by priority and the MAC address. If no priority is configured then all switches use the default priority and the election of the root bridge will be based on the lowest MAC address.