CCNA 4 Chapter 3: Point-to-Point Connections

Question 1

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

Answer 1

a single byte of binary 11111111

Question 2

How does PPP interface with different network layer protocols?

Answer 2

by using separate NCPs

Question 3

Match the PPP option with the correct description:

1. Compression
2. Multilink
3. Maximum Receive Unit
4. Authentication Protocol

Answer 3

1. Increase the effective throughput on PPP connection by reducing the amount of data in the frame that must travel across the link
2. Provide load balancing over the router interfaces
3. The maximum size of the PPP frame
4. The two choices are Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP)

Question 4

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

Answer 4

Router(config)# show controllers

Question 5

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

Answer 5

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

Question 6

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

Answer 6

LCP

Question 7

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

Answer 7

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

Question 8

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

Answer 8

option for authentication

Question 9

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

Answer 9

1. PPP can use synchronous and asynchronous circuits.
2. PPP uses LCPs to agree on format options such as authentication, compression, and error detection.
3. PPP uses LCPs to establish, configure, and test the data link connection.

Question 10

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

Answer 10

on a multilink interface

Question 11

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

Answer 11

FLAG

Question 12

Refer to the exhibit.

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

Answer 12

A PPP session was successfully established.

Question 13

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

Answer 13

1. Configure-Reject

2. Configure-Nak

Question 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.)

Answer 14

1. uses an unpredictable variable challenge value to prevent playback attacks
2. uses a three-way authentication periodically during the session to reconfirm identities
3. transmits login information in encrypted format

Question 15

Match the steps to the PPP CHAP authentication process sequence.
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6

Answer 15

1. Use LCP to negotiate the type of authentication
2. Calculate the ID and random number
3. Calculate the MD5 hash
4. Send Challenge ID, Hash, and username
5. Calculate the hash based on received information
6. Compare the received hash with the calculation hash

Question 16

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

Answer 16

1. LCP
2. NCP
3. HDLC-like framing

Question 17

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?​

Answer 17

The passwords do not match.

Question 18

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

Answer 18

Magic Number

Question 19

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

Answer 19

1. link-maintenance frames
2. link-termination frames
3. link-establishment frames

Question 20

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

Answer 20

Layer 1

Question 21

Match the phases off establishing PPP session in the correct order.

Answer 21

Phase 1: Establish the link and negotiate configuration options
Phase 2: Determine the quality of the link
Phase 3: negotiate with the network layer to configure L3 protocol.

Question 22

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

Answer 22

1. asynchronous serial
2. HSSI
3. synchronous serial

Question 23

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?

Answer 23

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

Question 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?

Answer 24

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