Review Questions

1. 

The Spanning Tree Protocol was created to overcome the problems of what type of bridging?

  1. Source route bridging

  2. Shorter path bridging

  3. Transparent bridging

  4. UplinkFast bridging

cthe spanning tree protocol was designed to help stop network loops that can happen with transparent bridge networks running redundant links.

2. 

Bridge Protocol Data Units (BPDUs) are responsible for providing information for which four services in a spanning tree?

  1. Determining the locations of data loops

  2. Electing a root bridge

  3. Monitoring the spanning tree

  4. Deciding the manufacturer’s MAC address on a physical interface

  5. Notifying other switches of network changes

a, b, c, ethe bridge protocol data units are sent out every 2 seconds by default and provide information to switches throughout the internetwork. this includes finding redundant links, electing the root bridge, monitoring the links in the spanning tree, and notifying other switches in the network about link failures.

3. 

On what VLAN are Bridge Protocol Data Units (BPDUs) sent by default?

  1. VLAN 64

  2. VLAN 1005

  3. VLAN 1

  4. VLAN 10

cvlan 1 is a default vlan and used for management by default.

4. 

Which of the following provides a separate instance of Spanning Tree Protocol for every VLAN?

  1. Common Spanning Tree (CST)

  2. Spanning Tree Algorithm (STA)

  3. Port Aggregation Protocol (PAgP)

  4. Per-VLAN Spanning Tree (PVST)

dthe cisco proprietary protocol per-vlan spanning tree (pvst) uses a separate instance of spanning tree for each and every vlan.

5. 

To configure a backup root bridge on a set-based switch, what command would be used?

  1. set spanning tree backup

  2. set spantree secondary

  3. set spantree root secondary

  4. spanning tree 2

cthe set spantree root secondary command enables you to configure a backup root bridge.

6. 

How many Spanning Tree Protocol instances are supported on the 2950 switch?

  1. 1005

  2. 10

  3. 512

  4. 64

dthe 2950 switch can support up to 1005 vlans but only up to 64 stp instances.

7. 

Which of the following would change the VLAN port priority on an IOS-based switch to a value of 16?

  1. spanning-tree vlan vlan_number priority 16

  2. spanning-tree priority 16

  3. config spantree priority 16

  4. spanning-tree priority 16 vlan vlan_number

aon an ios-based switch, use the spanning-tree vlan vlan_number priority 16 from interface configuration to change the port priority.

8. 

When setting the VLAN port priority, what are the available values you can use?

  1. 0–63

  2. 1–64

  3. 0–255

  4. 1–1005

aa priority from 0 to 63 can be set for each vlan.

9. 

When you’re using EtherChannel on your switches and a link failure occurs, what controlling device notifies the EARL of the failure?

  1. SAMBA

  2. CPU

  3. EBC

  4. SAINT

cshould one link in the bundle fail, the ethernet bundle controller (ebc) informs the enhanced address recognition logic (earl) asic of the failure, and the earl in turn ages out all addresses learned on that link.

10. 

From which of the following can PAgP form a bundle?

  1. Only statically assigned VLAN ports

  2. Dynamically assigned VLAN ports

  3. Dynamically and statically assigned VLAN ports

  4. Ports using different duplex types

apagp bundled ports must all be configured the same, including the duplex and speed. also, dynamic vlans will not work, so vlans must be assigned statically or must all be trunked ports.

11. 

What does the STP use to choose a forwarding port if the port costs are equal on a switch?

  1. Port ID

  2. MAC address

  3. Bridge name

  4. Hello timer

athe switch uses the port id to find the best forwarding port if the link costs are equal.

12. 

What is used to make a point-to-point port enter almost immediately into forwarding state by decreasing the time of the listening and learning states?

  1. PortUp

  2. PortFast

  3. Priority

  4. BackboneFast

bportfast is used to put a blocked port into forwarding state immediately upon a bootup of a point-to-point device such as a workstation or server.

13. 

What protocol sends Root Link Query BPDUs upon receiving an inferior BPDU?

  1. PortUp

  2. PortFast

  3. Priority

  4. BackboneFast

dwhen backbonefast is turned on, the root link query bpdus are sent out as soon as an inferior bpdu is received. this can enable faster convergence in the event of a backbone link failure.

14. 

Which of the following commands is used to create a bundle on a 4000 series switch?

  1. port set channel

  2. set port channel

  3. etherchannel on

  4. set bundle slot/port

bthe command set port channel slot/port [on/off] is used to create an etherchannel bundle.

15. 

Which of the following global configuration commands is used to turn on BackboneFast on an IOS-based switch?

  1. port channel backbonefast

  2. spanning-tree backbonefast

  3. spantree backbonefast

  4. enable spanning-tree backbone-fast

bto enable backbonefast on an ios-based switch, use the spanning-tree backbonefast command, which turns the protocol on for every vlan.

16. 

Which of the following is true regarding PVST+? (Choose all that apply.)

  1. It is a Cisco proprietary protocol.

  2. It adds checking mechanisms to make sure there are no configuration problems on trunked ports and VLAN IDs across switches.

  3. It is set on a port-by-port basis.

  4. It enables Cisco switches to support the IEEE 802.1Q standard.

a, b, dpvst is proprietary to cisco, and pvst + is an extension of pvst. pvst + enables non- pvst information to be accepted and received into pvst, adds configuration checking, and enables cisco switches to support 802.1q.

17. 

What is the IEEE implementation of the STP?

  1. CST

  2. PVST

  3. PVST+

  4. 802.1u

athe ieee uses what is called common spanning tree (cst), which is defined with ieee 802.1q. the ieee 802.1q defines one spanning tree instance for all vlans.

18. 

How many spanning tree instances are defined with the PVST protocol running on a switch with six VLANs configured?

  1. 1005

  2. 1

  3. 6

  4. 64

cthe pvst protocol defines one instance of stp per vlan.

19. 

How many spanning tree instances are defined with the CST protocol running on a switch with six VLANs configured?

  1. 1005

  2. 1

  3. 6

  4. 64

bthe cst protocol defines one instance of stp per network regardless of the number of vlans configured.

20. 

Which three of the following can STP use to determine the best path to the root bridge?

  1. STP protocol

  2. Port cost

  3. Path cost

  4. Bridge priority

  5. Port priority

b, c, ethe port cost, path cost, and port priority are used to determine the best path to the root bridge.

Answers

1. 

C The Spanning Tree Protocol was designed to help stop network loops that can happen with transparent bridge networks running redundant links.

2. 

A, B, C, E The Bridge Protocol Data Units are sent out every 2 seconds by default and provide information to switches throughout the internetwork. This includes finding redundant links, electing the root bridge, monitoring the links in the spanning tree, and notifying other switches in the network about link failures.

3. 

C VLAN 1 is a default VLAN and used for management by default.

4. 

D The Cisco proprietary protocol Per-VLAN Spanning Tree (PVST) uses a separate instance of spanning tree for each and every VLAN.

5. 

C The set spantree root secondary command enables you to configure a backup root bridge.

6. 

D The 2950 switch can support up to 1005 VLANs but only up to 64 STP instances.

7. 

A On an IOS-based switch, use the spanning-tree vlan vlan_number priority 16 from interface configuration to change the port priority.

8. 

A A priority from 0 to 63 can be set for each VLAN.

9. 

C Should one link in the bundle fail, the Ethernet Bundle Controller (EBC) informs the Enhanced Address Recognition Logic (EARL) ASIC of the failure, and the EARL in turn ages out all addresses learned on that link.

10. 

A PAgP bundled ports must all be configured the same, including the duplex and speed. Also, dynamic VLANs will not work, so VLANs must be assigned statically or must all be trunked ports.

11. 

A The switch uses the port ID to find the best forwarding port if the link costs are equal.

12. 

B PortFast is used to put a blocked port into forwarding state immediately upon a bootup of a point-to-point device such as a workstation or server.

13. 

D When BackboneFast is turned on, the Root Link Query BPDUs are sent out as soon as an inferior BPDU is received. This can enable faster convergence in the event of a backbone link failure.

14. 

B The command set port channel slot/port [on/off] is used to create an EtherChannel bundle.

15. 

B To enable BackboneFast on an IOS-based switch, use the spanning-tree backbonefast command, which turns the protocol on for every VLAN.

16. 

A, B, D PVST is proprietary to Cisco, and PVST+ is an extension of PVST. PVST+ enables non- PVST information to be accepted and received into PVST, adds configuration checking, and enables Cisco switches to support 802.1Q.

17. 

A The IEEE uses what is called Common Spanning Tree (CST), which is defined with IEEE 802.1Q. The IEEE 802.1Q defines one spanning tree instance for all VLANs.

18. 

C The PVST protocol defines one instance of STP per VLAN.

19. 

B The CST protocol defines one instance of STP per network regardless of the number of VLANs configured.

20. 

B, C, E The port cost, path cost, and port priority are used to determine the best path to the root bridge.



CCNP. Building Cisco Multilayer Switched Networks Study Guide (642-811)
CCNP: Building Cisco Multilayer Switched Networks Study Guide (642-811)
ISBN: 078214294X
EAN: 2147483647
Year: 2002
Pages: 174
Authors: Terry Jack

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