350-001 Written: Spanning Tree & VTP Part 3

1. Refer to the exhibit above. The Layer 2 network uses VTP to manage its VLAN database. A network designer created all VLANs on the VTP server (switch 1) and it has been advertised through VTP to all other VTP clients (switches 2 through 4). Due to network growth, a network operator decided to add a new switch between switch 1 and switch 3. The network operator has been instructed to use a refurbished switch and make it a VTP client. Which three of these factors should the network operator consider to minimize the impact of adding a new switch? (Choose three)

A. Pay special attention to the VTP revision number, because the higher value takes the priority

B. Configure all VLANs manually on the new switch in order to avoid connectivity issuesC. A trunk should be established between the new switch and switches 1 and 3 as VTP only runs over trunk links.
D. Set at least the VTP domain name and password to get the new switch synchronized

E. An ISL trunk should be established between the new switch and switches 1 and 3, because VTP only runs over ISL

F. Pay special attention to the VTP revision number, because the lower value takes the priorityAnswer: A,C,D
Explanation: http://www.cisco.com/en/US/tech/tk389/tk689/technologies_configuration_example09186a0080890607.shtml#conf

2. Before inserting a new switch in the network, the network administrator checks that the VTP domain name is correct, the VTP mode is set to server, and revision is lower than the switches in the network. The administrator then configures interfaces and trunks, erases existing VLANs, and connects the switch to the network. Following that procedure, there is no connectivity in the network. What is a possible cause of this problem?

A. Because the configuration revision of the new switches is lower than the rest of the network, it can change the VLAN database of the other switches

B. As a VTP server, the new switch deleted all VLANs of the network

C. Erasing VLANs increases the VTP configuration revision

D. Since the configuration revision of the network is higher than the new switch, the VLANAnswer: C
Explanation: This answer is directly implied by the following URL on troubleshooting the VTP config revision numberhttp://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080890613.shtml#topic14

3. Network A has a spanning-tree problem in which the traffic is selecting a longer path. How is the path cost calculated? number of hops priority of the bridge interface bandwidth interface delay None of the above
database was automatically synchronized.

A. number of hops

B. priority of the bridge

C. interface bandwidth

D. interface delay

E. None of the aboveAnswer: C
Explanation: reference previous STP questions where interface bandwidth was the answer for path cost.

4. You deployed new fibers in your network to replace copper spans that were too long. While reconnecting the network, you experienced network problems because you reconnected wrong fibers to wrong ports. What could you do to prevent this type of problem in the future, particularly when connecting and reconnecting fiber pairs?

A. Only use fiber in pairs

B. Configure root guard on your switches

C. Do not use fiber but use copper

D. Configure UDLD to prevent one-way link conditionsAnswer: D
Explanation: http://www.cisco.com/en/US/docs/switches/lan/catalyst3550/software/release/12.1_19_ea1/configuration/guide/swudld.html#wp1020819

5. While deploying a new switch, you accidentally connect ports 3/12 and 3/18 together, creating a loop. STP detected it and placed port 3/18 in blocking mode. Why did STP not place port 3/12 in blocking mode instead?

A. Port 3/12 was already up and forwarding before the loop was created

B. Port priority is based on lowest priority and lowest port number

C. You connected the wire on port 3/18 last

D. None of the above, it is purely random

Answer: B

Explanation: "If all ports have the same priority value, the port with the lowest port number forwards frames." from the following URL http://www.cisco.com/en/US/docs/switches/lan/catalyst4000/7.4/configuration/guide/spantree.html#wp1138416

6. Prior to 802.1w, Cisco implemented a number of proprietary enhancements to 802.1D to improve convergence in a Layer 2 network. Which statement is correct?

A. Only UplinkFast and BackboneFast are specified in 802.1w; PortFast must be manually configured

B. Only PortFast is specified in 802.1w; UplinkFast and BackboneFast must be manually configured.
C. None of the proprietary Cisco enhancements are specified in 802.1w. PortFast, UplinkFast, and BackboneFast are specified in 802.1w.

D. PortFast, UplinkFast, and BackboneFast are specified in 802.1w

Answer: D

Explanation: see the 802.1w RSTP specifications at the URL belowhttp://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cfa.shtml#intro

7. As a network administrator, can you tell me what the root guard feature provides in a bridged network?

A. It ensures that BPDUs sent by the root bridge are forwarded in a timely manner

B. It enforces the root bridge placement in the networkC. It ensures that all ports receiving BPDUs from the root bridge are in the forwarding state
D. It ensures that the bridge is elected as root bridge in the network

Answer: B

Explanation: http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00800ae96b.shtml#feature

8. If a Cisco switch is configured with VTPv1 in transparent mode, what is done with received VTP advertisements?

A. They are discarded

B. The contents are altered to reflect the switch's own VTP database and then they are forward
out all trunking ports

C. The changes within the advertisements are made to the switch's VTP databaseD. The contents are ignored and they are forwarded out all trunking ports.
Answer: A

Explanation: "However, in VTP version 2, transparent switches do forward VTP advertisements that they receive from other switches from their trunk interfaces" fromhttp://www.cisco.com/en/US/docs/switches/lan/catalyst2950/software/release/12.1_9_ea1/configuration/guide/swvtp.html


9. Refer to the following descriptions, which three are true about Cisco spanning-tree features? (Choose three)

A. RPVST+ converges faster than RSTP during a topology change

B. STP BPDUs are relayed by all non-root bridges and RSTP BPDUs are generated by each bridge.

C. RSTP can only achieve rapid transition to Forwarding on edge ports and on point-to-point links

D. RPVST+ and RSTP are both based upon the IEEE 802.1w specification.

Answer: B,C,D

Explanation: some helpful RPVST+ info can be found athttp://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

10. When two bridges are competing for the root bridge of an IEEE 802.1D spanning tree and both have the same bridge priority configured, which parameter determines the winner?

A. highest-numbered IP interface

B. MAC address

C. device uptime
D. root port cost

Answer: B

Explanation: know your 802.1D