CCNA 4 R&S: Connecting Networks Chapter 3 v5.02 + v5.03 Exam Answers 2016

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

a single byte of binary 10101010
a single byte of binary 11111111*
the IP address of the serial interface
a single byte of binary 00000000

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

by specifying the protocol during link establishment through LCP
by encoding the information field in the PPP frame
by using separate NCPs*
by negotiating with the network layer handler

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

Place the options in the following order:
Compression -> Increases the effective throughput on PPP connections by reducing the amount of data in the frame that must travel across the link.
Multilink -> Provides load balancing over the router interfaces.
Maximum Receive Unit -> The maximum size of the PPP frame
– not scored –
Authentication Protocol -> The two choices are Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP)

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

Router(config)# show controllers*
Router(config)# show ip interface
Router(config)# show interfaces
Router(config)# show ip interface brief

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

when plain text passwords are needed to simulate login at the remote host*
when router resources are limited
when multilink PPP is used
when a network administrator prefers it because of ease of configuration

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



Refer to the exhibit. Which statement describes the status of the PPP connection?

Both the link-establishment and network-layer phase completed successfully.*
Only the network-layer phase completed successfully.
Only the link-establishment phase completed successfully.
Neither the link-establishment phase nor the network-layer phase completed successfully.

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

option for session establishment
higher speed transmission
option for authentication*
fixed-size frames

9. Which three statements are true about PPP? (Choose three.)

PPP can use synchronous and asynchronous circuits.*
PPP carries packets from several network layer protocols in LCPs.
PPP can only be used between two Cisco devices.
PPP uses LCPs to agree on format options such as authentication, compression, and error detection.*
PPP uses LCPs to establish, configure, and test the data link connection.*

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

on a subinterface
on a physical serial interface
on a physical Ethernet interface
on a multilink interface*

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



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

Both PAP and CHAP authentication were attempted.
A PPP session was successfully established.*
CHAP authentication failed because of an unknown hostname.
The debug output is from router R2.

13. During a PPP session establishment phase, which two messages are sent by the requested party if the options are not acceptable? (Choose two.)


14. A network administrator is evaluating authentication protocols for a PPP link. Which three factors might lead to the selection of CHAP over PAP as the authentication protocol? (Choose three.)

uses an unpredictable variable challenge value to prevent playback attacks*
uses a three-way authentication periodically during the session to reconfirm identities*
transmits login information in encrypted format*
control by the remote host of the frequency and timing of login events
establishes identities with a two-way handshake
makes authorized network administrator intervention a requirement to establish each session

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

Place the options in the following order:
Step 3 -> calculate the MD5 hash
Step 2 -> calculate the ID and random number
Step 4 -> send challenge ID, hash, and username
Step 1 -> use LCP to negotiate the type of authentication
– not scored –
Step 5 -> calculate the hash based on received information
Step 6 -> compare the received hash with the calculated hash

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

HDLC-like framing*



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.

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

Magic Number*

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

link-negotiation frames
link-acknowledgment frames
link-maintenance frames*
link-termination frames*
link-establishment frames*
link-control frames

20. At which layer of the OSI model does multiplexing take place?

Layer 3
Layer 4
Layer 2
Layer 1*

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

Place the options in the following order:
Phase 3  -> negotiate with the network layer to configure L3 protocol
– not scored –
Phase 1  -> establish the link and negotiate configuration options
Phase 2 -> determine the quality of the link

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

asynchronous serial*
synchronous serial*



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 encapsulation in both routers does not match.
The passwords are different in both routers.
In each case the expected username is not the same as the remote router hostname.*
The authentication type is not the same in both routers.

24. 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 down
Serial 0/0/0 is administratively down, line protocol is down
Serial 0/0/0 is up (disabled)
Serial 0/0/0 is up, line protocol is up
Serial 0/0/0 is down, line protocol is down*
Serial 0/0/0 is up (looped)

25. What PPP information will be displayed if a network engineer issues the show ppp multilink command on Cisco router?
the IP addresses of the link interfaces
the serial interfaces participating in the multilink*
the queuing type on the link
the link LCP and NCP status

26. 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
RtrA(config-if)# no shutdown


Frame Relay



27.  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?

Issue the command ppp quality 70.*
Issue the command ppp quality 100.
Set the DCE interface to a lower clock rate.
Use the bandwidth command to increase the bandwidth of the link.

28. 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.
The compress command was used when PPP was configured on the interfaces.*
The clock rates configured on each serial interface do not match.
PAP authentication was misconfigured on the link interfaces.