Chapter 3 Review

show spanning-tree

An administrator is troubleshooting a switch and wants to verify if it is a root bridge. What command can be used to do this?

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

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?

Lowest MAC address

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

Learning Forwarding

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

2

The default hello timer value for STP BPDU frames is_________________________________ seconds.

mode rapid-pvst

The spanning-tree ___________________ global configuration command is used to enable Rapid PVST+.

The root bridge BID. The role of the ports in all VLANs

To obtain an overview of the spanning tree status of a switched network, a network engineer issues the show spanning-tree command on a switch. Which two items of information will this command display? (Choose two.)

VLAN ID

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

Broadcast frames are forwarded back to the sending switch.

What is a characteristic of a Layer 2 loop?

designing a network to use multiple paths between switches to ensure there is no single point of failure

What is an accurate description of redundancy?

PVST+ optimizes performance on the network through load sharing.

What is an advantage of PVST+?

Manually remove redundant links in the switched network.

What is one way to correct a spanning tree failure?

New traffic is discarded by the switch because it is unable to be processed.

What is the outcome of a Layer 2 broadcast storm?

prevents Layer 2 loops

What is the purpose of the Spanning Tree Protocol (STP)?

StackWise

What port type is used to interconnect switches in a switch stack?

MAC address

What value determines the root bridge when all switches connected by trunk links have default STP configurations?

Listening

When PVST is running over a switched network, which port state can participate in BPDU frame forwarding based on BPDUs received, but does not forward data frames?

BPDU guard

Which Cisco switch feature ensures that configured switch edge ports do not cause Layer 2 loops if a port is mistakenly connected to another switch?

Edge Ports

Which RSTP ports are connected to end devices?

Root Port

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

spanning-tree vlan 10 priority 0

Which STP priority configuration would ensure that a switch would always be the root switch?

PVST+

Which is the default STP operation mode on Cisco Catalyst switches?

Forwarding

Which port state will switch ports immediately transition to when configured for PortFast?

MST

Which protocol provides up to 16 instances of RSTP, combines many VLANs with the same physical and logical topology into a common RSTP instance, and provides support for PortFast, BPDU guard, BPDU filter, root guard, and loop guard?

802.1D

Which spanning tree standard supports only one root bridge so that traffic from all VLANs flows over the same path?

bridge priority extended system ID MAC address

Which three components are combined to form a bridge ID?

discarding Learning Forwarding

Which three port states are used by Rapid PVST+? (Choose three.)

Edgeport PortFast

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.)

Due to high processing demands during a broadcast storm, communication may fail between end stations in the broadcast domain. During a broadcast storm, constant changes to the MAC address table prevent a switch from accurately forwarding frames.

Which two issues are the result of a broadcast storm? (Choose two.)

STP

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

Link types are determined automatically

A network administrator is preparing the implementation of Rapid PVST+ on a production network. How are the Rapid PVST+ link types determined on the switch interfaces?

Each switch will analyze the sum of all port costs to reach the root and use the path with the lowest cost.

After the election of the root bridge has been completed, how will switches find the best paths to the root bridge?

redundant links between Layer 2 switches removing single points of failure with multiple Layer 2 switches

Which two network design features require Spanning Tree Protocol (STP) to ensure correct network operation? (Choose two.)

The switch port immediately transitions from blocking to the forwarding state. The switch port should never receive BPDUs.

Which two statements describe a switch port that is configured with PortFast? (Choose two.)

RSTP STP

Which two types of spanning tree protocols can cause suboptimal traffic flows because they assume only one spanning-tree instance for the entire bridged network? (Choose two.)

MSTP

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