CCNA v4 - E4 - Module 2 (100%)

1. Refer to the exhibit. What can be concluded about the function of the Serial 0/0/0 interface on the router after the commands are entered?

The serial link will be closed if the number of received packets at the destination node falls below 90 percent of the packets that are sent.

2. Refer to the exhibit. While troubleshooting a serial interface, a technician enters the command show interface serial 0/0/0 . If the interface is in DCE mode, what two problems are likely to cause the indicated problem? (Choose two.)

The remote CSU or DSU has failed.

A timing problem has occurred on the cable.

3. Refer to the exhibit. What statement is true regarding the output shown? The PAP passwords did not match, so the routers are trying CHAP authentication.4. Why are serial connections preferred over parallel connections for long transmission lengths?

Parallel connections are subject to clock skew and to crosstalk between wires.

5. Which two statements are true about time-division multiplexing (TDM)? (Choose two.)

Multiple sources can transmit over a single channel.

Original data streams must be reconstructed at the destination.

6. Which authentication protocol can be spoofed to allow playback attacks?

PAP

7. What function do Network Control Protocols provide for a PPP connection?

to allow multiple Layer 3 protocols to operate over the same physical link

8. Refer to the exhibit. Router R1, the DCE device, has just been configured for PPP encapsulation with authentication. What series of commands will allow another router, the DTE device, to communicate over its serial 0/0/0 interface to router R1?

Router(config)# hostname R3

R3(config)# username R1 password Cisco

R3(config)# interface Serial 0/0/0

R3(config-if)# encapsulation ppp

R3(config-if)# ip address 172.16.3.3 255.255.255.0

R3(config-if)# ppp authentication chap

9. What advantage does PPP have over HDLC for serial communications?

It supports authentication

10. Which PPP configuration option can be used to establish load balancing over the interfaces of a router?

multilink

11. Which three statements are correct about HDLC encapsulation? (Choose three.)

HDLC implementation in Cisco routers is proprietary.

HDLC is the default serial interface encapsulation on Cisco routers.

HDLC uses frame delimiters to mark the beginnings and ends of frames.

12. Refer to the exhibit. Router R1 is not able to communicate with a neighbor router that is directly connected to serial 0/0/0. What is the reason for this?

The interface has been administratively shutdown with the shutdown command.

13. Refer to the exhibit. What statement is true regarding the output shown?

Data is able to flow across this link.

14. Which serial communications DTE/DCE interface standard is used to provide high-speed connectivity of up to 52 Mbps between LANs and is found on many high-end Cisco routers?

EIA/TIA-612/613 (HSSI)

15. What does the demarcation point represent in data communication physical circuits?

physical point at which the public network ends and the private customer network begins

16. Which three statements are true regarding LCP? (Choose three.)

It is responsible for negotiating link establishment.

It terminates the link upon user request or the expiration of an inactivity timer.

It can test the link to determine if link quality is sufficient to bring up the link.

17. Refer to the exhibit. Which two statements are true regarding the output shown? (Choose two.)

The router has agreed on IP parameters.

The router has negotiated LCP successfully.

18. Refer to the exhibit. Which statement is true about PPP operation?

Both the link-establishment and network-layer phase completed successfully.

19. Which three statements correctly describe PPP authentication? (Choose three.)

PAP sends passwords in clear text.

CHAP uses a challenge/response that is based on the MD5 hash algorithm.

CHAP uses repeated challenges for verification.

20. Which two options can LCP negotiate? (Choose two.)

link quality authentication

21. Refer to the exhibit. On the basis of the show interface Serial0/0 output, how many NCP sessions have been established?

two

CCNA 4 Module 1 V4.0

1. Which statement about WAN protocols is correct?

Most WAN protocols use HDLC or a variant of HDLC as a framing mechanism.

2. Which statement is true of the functionality of the layers in the hierarchical network model?

The distribution layer aggregates WAN connections at the edge of the campus.

3. Which WAN technology uses a fixed payload of 48 bytes and is transported across both switched and permanent virtual circuits?

ATM

4. A U.S. company requires a WAN connection used only to transfer sales data from individual stores to the home office. All transfers will occur after business hours. The required bandwidth for this connection is estimated to be less than 38 kbps. Which type of connection requires the least investment for this company?

analog dialup

5. What is an advantage of packet-switched technology over circuit-switched technology?

Packet-switched networks can efficiently use multiple routes inside a service provider network.

6. Which statement is true about data connectivity between a customer and a service provider?

The segment between the demarcation point and the central office is known as the "last mile."

7. What are two advantages of an analog PSTN WAN connection? (Choose two.)

low cost
availability

8. What can cause a reduction in available bandwidth on a cable broadband connection?

number of subscribers

9. For digital lines, which device is used to establish the communications link between the customer equipment and the local loop?

CSU/DSU

10. At which two layers of the OSI model does a WAN operate? (Choose two.)

Physical Layer
Data Link Layer

11. A company needs a WAN connection that is capable of transferring voice, video, and data at a minimum data rate of 155 Mbps. Which WAN connection is the best choice?

ATM

12. Which statement is true about the differences between a WAN and a LAN?

A WAN often relies on the services of carriers, such as telephone or cable companies, but a LAN does not.

13. Which networking device is typically used to concentrate the dial-in and dial-out traffic of multiple users to and from a network?

access server

14. Why is the call setup time of a circuit-switched WAN implementation considered a drawback?

Data cannot be transferred until a circuit has been established.

15. What three terms are associated with ISDN PRI? (Choose three.)

circuit switching
data bearer channels
time-division multiplexing

16. Which three features are identified with Frame Relay connections? (Choose three.)
CIR
DLCI
PVC

17. Which two devices are commonly used as data communications equipment? (Choose two.)

Modem
CSU/DSU

18. Which packet-switched WAN technology offers high-bandwidth connectivity capable of managing data, voice, and video all on the same infrastructure?

metro Ethernet

19. Which three WAN devices can be found in the cloud? (Choose three.)

ATM switches
core routers
Frame Relay switches

20. Which switching type will allow the communication devices in the provider network to be shared and only allocated to an individual subscriber during data transfer?

dedicated switched lines

21. What type of connectivity is established when VPNs are used from the remote site to the private network?

Tunnels

22. Which term describes a device that will put data on the local loop?

DCE