CCNA 4 Chapter 2 V6.0 Answers

1. A network engineer is troubleshooting the loss of MPEG video viewing quality as MPEG video files cross a PPP WAN link. What could be causing this loss of quality?

Link Quality Monitoring was not configured correctly on each interface.

PAP authentication was misconfigured on the link interfaces.

The compress command was used when PPP was configured on the interfaces.

The clock rates configured on each serial interface do not match.

 

2. Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.

Why is the serial link between router R1 and router R2 not operational?

The authentication type is not the same in both routers.

The passwords are different in both routers.

In each case the expected username is not the same as the remote router hostname.

The encapsulation in both routers does not match.

 

3. Which protocol will terminate the PPP link after the exchange of data is complete?

NCP

IPCP

IPXCP

LCP

 

4. Which two statements describe a PPP connection between two Cisco routers? (Choose two.)

With CHAP authentication, the routers exchange plain text passwords.

LCP tests the quality of the link.

LCP manages compression on the link.

NCP terminates the link when data exchange is complete.

Only a single NCP is allowed between the two routers.

 

5. In which situation would the use of PAP be preferable to the use of CHAP?

when router resources are limited

when multilink PPP is used

when a network administrator prefers it because of ease of configuration

when plain text passwords are needed to simulate login at the remote host

 

6. When configuring Multilink PPP, where is the IP address for the multilink bundle configured?

on a subinterface

on a physical serial interface

on a multilink interface

on a physical Ethernet interface

 

7. A laptop is connected to an AP and is associated with the connection that is labeled A. The AP is connected to a switch and is associated with the connection that is labeled B. A PC is attached to the switch. The switch is connected to router RTA. The connection of the PC, through the switch, to RTA is associated with the connection that is labeled C. RTA is connected via a serial connection to the ISP and is associated with the connection labeled D.

Refer to the exhibit. What type of Layer 2 encapsulation will be used for connection D on the basis of this configuration on a newly installed router:

RtrA(config)# interface serial0/0/0

RtrA(config-if)# ip address 128.107.0.2 255.255.255.252

RtrA(config-if)# no shutdown

Frame Relay

Ethernet

PPP

HDLC

 

8. Which address is used in the Address field of a PPP frame?

A single byte of binary 10101010

the IP address of the serial interface

a single byte of binary 00000000

a single byte of binary 11111111

 

9. Match the steps to the PPP CHAP authentication process sequence. (Not all options are used.)

calculate the MD5 hash => Step 3

calculate the ID and random number => Step 2

send the challenge ID, hash, and username => Step 4

use LCP to negotiate the type of authentication => Step 1

calculate the hash based on received information => Step 5

compare the received hash with the calculated hash => Step 6

 

10. How does PPP interface with different network layer protocols?

by negotiating with the network layer handler

by specifying the protocol during link establishment through LCP

by using separate NCPs

by encoding the information field in the PPP frame

 

11. Match the PPP options with the correct description. (Not all options are used.)

Increases the effective throughput on PPP connections by reducing the amount of data in the frame that must travel across the link. => Compression

Provides load balancing over the router interfaces. => Multilink

The maximum size of the PPP frame. => Maximum Receive Unit

The two choices are Password Authentication Protocol (PAP) and chanllenge Handshake Authentication Protocol (CHAP). => Authentication Protocol

 

12. Which field marks the beginning and end of an HDLC frame?

Data

Control

FCS

Flag

 

13. Which serial 0/0/0 interface state will be shown if no serial cable is attached to the router, but everything else has been correctly configured and turned on?

Serial 0/0/0 is up, line protocol is up

Serial 0/0/0 is up (disabled)

Serial 0/0/0 is up (looped)

Serial 0/0/0 is up, line protocol is down

Serial 0/0/0 is down, line protocol is down

Serial 0/0/0 is administratively down, line protocol is down

 

14. Which three are types of LCP frames used with PPP? (Choose three.)

link-control frames

link-termination frames

link-establishment frames

link-negotiation frames

link-maintenance frames

link-acknowledgment frames

 

15. A network engineer is monitoring an essential, but poor quality, PPP WAN link that periodically shuts down. An examination of the interface configurations shows that the ppp quality 90 command has been issued. What action could the engineer take to reduce the frequency with which the link shuts down?

Use the bandwidth command to increase the bandwidth of the link.

Issue the command ppp quality 70.

Issue the command ppp quality 100.

Set the DCE interface to a lower clock rate.

 

16. How much total bandwidth is provided by a T1 line?

1.544 Mb/s

43.736 Mb/s

64 kb/s

128 b/s

 

17. Which PPP option can detect links that are in a looped-back condition?

MRU

Magic Number

Callback

ACCM

 

18. Which is an advantage of using PPP on a serial link instead of HDLC?

option for authentication

option for session establishment

fixed-size frames

higher speed transmission

 

19. What are three components of PPP? (Choose three.)

parallel communications

support for LAN and WAN

authorization

NCP

LCP

HDLC-like framing

 

20. Match the phases of establishing a PPP session in the correct order. (Not all options are used.)

negotiate with the network layer to configure L3 protocol => phase 3

establish the link and negotiate configuration options => phase 1

determine the quality of the link => phase 2

 

21. The exhibit displays some partial debug command output:

Refer to the exhibit. Based on the debug command output that is shown, which statement is true of the operation of PPP.

CHAP authentication failed because of an unknown hostname.

The debug output is from router R2.

A PPP session was successfully established.

Both PAP and CHAP authentication were attempted.

 

22. Which command can be used to view the cable type that is attached to a serial interface?

Router(config)# show interfaces

Router(config)# show ip interface brief

Router(config)# show ip interface

Router(config)# show controllers

 

23. A network engineer has issued the show interfaces serial 0/0/0 command on a router to examine the open NCPs on a PPP link to another router. The command output displays that the encapsulation is PPP and that the LCP is open. However, the IPV6CP NCP is not shown as open. What does the engineer need to configure to open the IPV6CP NCP on the link?

Configure CHAP authentication on each router.

Issue the compress predictor command on each interface on the link.

Configure PPP multilink interfaces on each router.

Configure an Ipv6 address on each interface on the link.

 

24. The exhibit has two boxes. The first box shows the following partial command output:

Refer to the exhibit. A network administrator is configuring the PPP link between the two routers. However, the PPP link cannot be established. Based on the partial output of the show running-config command, what is the cause of the problem?

The passwords do not match.

The usernames do not match.

The passwords should be longer than 8 characters.

The interface IP addresses are in different subnets.

 

25. Which three physical layer interfaces support PPP? (Choose three.)

Ethernet

GigabitEthernet

asynchronous serial

FastEthernet

synchronous serial

HSSI