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Saturday, November 17, 2007

Implement and verify WAN links


CCNA (640-802) topic Implement and Verify WAN links answers the questions from this topic in exam.

Question 1:
A default Frame Relay WAN is classified as what type of physical network?
A: point-to-point
B: broadcast multi-access
C: nonbroadcast multi-access
D: nonbroadcast multipoint
E: broadcast point-to-multipoint

Answers: C

Question 2:
The command frame-relay map ip 10.121.16.8 102 broadcast was entered on the router. Which of the following statements is true concerning this command?
A: This command should be executed from the global configuration mode.
B: The IP address 10.121.16.8 is the local router port used to forward data.
C: 102 is the remote DLCI that will receive the information.
D: This command is required for all Frame Relay configurations.
E: The broadcast option allows packets, such as RIP updates, to be forwarded across the PVC.

Answers: E

Explanation:
When the frame-relay map command is included in the configuration with the broadcast keyword, it turns Frame Relay network as a broadcast network.

Question 3:
Refer to the exhibit. Which statement describes DLCI 17?

A: DLCI 17 describes the ISDN circuit between R2 and R3.
B: DLCI 17 describes a PVC on R2. It cannot be used on R3 or R1.
C: DLCI 17 is the Layer 2 address used by R2 to describe a PVC to R3.
D: DLCI 17 describes the dial-up circuit from R2 and R3 to the service provider.

Answers: C

Question 4:
How should a router that is being used in a Frame Relay network be configured to avoid split horizon issues from preventing routing updates?
A: Configure a separate sub-interface for each PVC with a unique DLCI and subnet assigned to the sub-interface.
B: Configure each Frame Relay circuit as a point-to-point line to support multicast and broadcast traffic.
C: Configure many sub-interfaces on the same subnet.
D: Configure a single sub-interface to establish multiple PVC connections to multiple remote router interfaces.

Answers: A

Question 5:
What can a network administrator utilize by using PPP Layer 2 encapsulation? (Choose three.)
A:VLAN support
B:compression
C:authentication
D:sliding windows
E:multilink support
F:quality of service

Answers: B, C, E

Question 6:
Refer to the exhibit. What is the meaning of the term dynamic as displayed in the output of the show frame-relay map command shown?

A: The Serial0/0 interface is passing traffic.
B: The DLCI 100 was dynamically allocated by the router.
C: The Serial0/0 interface acquired the IP address of 172.16.3.1 from a DHCP server.
D: The DLCI 100 will be dynamically changed as required to adapt to changes in the Frame Relay cloud.
E: The mapping between DLCI 100 and the end station IP address 172.16.3.1 was learned through Inverse ARP.

Answers: E

Explanation:
Inverse ARP allows a Frame Relay network to discover the protocol address associated with the virtual circuit dynamically.

Question 7:
Which of the following describes the roles of devices in a WAN? (Choose three.)
A:A CSU/DSU terminates a digital local loop.
B:A modem terminates a digital local loop.
C:A CSU/DSU terminates an analog local loop.
D:A modem terminates an analog local loop.
E:A router is commonly considered a DTE device.
F:A router is commonly considered a DCE device.

Answers: A, D, E

Question 8:
Which three Layer 2 encapsulation types would be used on a WAN rather than a LAN? (Choose three.)
A:HDLC
B:Ethernet
C:Token Ring
D:PPP
E:FDDI
F:Frame Relay

Answers: A, D, F

Question 9:
The Frame Relay network in the diagram is not functioning properly. What is the cause of the problem?

A: The Gallant router has the wrong LMI type configured.
B: Inverse ARP is providing the wrong PVC information to the Gallant router.
C: The S3 interface of the Steele router has been configured with the frame-relay encapsulation ietf command.
D: The frame-relay map statement in the Attalla router for the PVC to Steele is not correct.
E: The IP address on the serial interface of the Attalla router is configured incorrectly.

Answers: D

Explanation:
In above exhibit we need to look at the status of each PVC to identify the problem.
At atlanta we find the show command for first Map status deleted. Which is the PVC to Steele because the next map statement in show command is for Gallant and its status is active.


Question 10:
Which of the following are key characteristics of PPP? (Choose three.)
A:can be used over analog circuits
B:maps Layer 2 to Layer 3 address
C:encapsulates several routed protocols
D:supports IP only
E:provides error correction

Answers: A, C, E

Question 11:
A Cisco router that was providing Frame Relay connectivity at a remote site was replaced with a different vendor's frame relay router. Connectivity is now down between the central and remote site. What is the most likely cause of the problem?
A: incorrect IP address mapping
B: mismatched encapsulation types
C: incorrect DLCI
D: mismatched LMI types

Answers: B

Question 12:
Refer to the exhibit. The network administrator must complete the connection between the RTA of the XYZ Company and the service provider. To accomplish this task, which two devices could be installed at the customer site to provide a connection through the local loop to the central office of the provider? (Choose two.)

A:WAN switch
B:PVC
C:ATM switch
D:multiplexer
E:CSU/DSU
F:modem

Answers: E, F

Question 13:
When a router is connected to a Frame Relay WAN link using a serial DTE interface, how is the interface clock rate determined?
A: It is supplied by the CSU/DSU.
B: It is supplied by the far end router.
C: It is determined by the clock rate command.
D: It is supplied by the Layer 1 bit stream timing.

Answers: A


Post a comment if you need explanation to any of the above questions!!!!!!

5 comments:

Anonymous said...

Wonderful job, as always. My question is about #9.

the basic syntax for a map statement is remoteIP localDLCI.

if the diagram is correct, the map statement for steele uses its localIP, as does the first mapping on Attalla.

Am I wrong?

Also, for #11, to me it seems a toss-up between B and D (encap vs LMI). did you choose B simply because encap is configured first?

Keep up the fantastic work!
-john

Anonymous said...

great effort

can u explain subnetting , summerisation questions also

a3tips said...

Hi John,

Q11.. Since the router was replaced the default encaspsulation on interfaces is HDLC which is different to already configured routers encapsulation frame relay on other side.. moreover most of IOS have autosense LMI capabilities.

Q9..

Yes steele map statement is also wrongly written but since the question answer options only have about Attalla router PVC to Steele is not correct.
Nothing is mentioned about the steelle map statement in options thats the reason i have selected option D.

Hope this helps
Cheers!!!

a3tips said...

Hi,

For subneting and summarization please check old topic on the site it is already explained.

Cheers!!!

CapeCod said...

The diagram is incorrect: the router on the right side should be Steele, and Attalla is a middle router's name!
Just change this names - and correct answer will be obvious ;)

CapeCod