CCNA 4 Chapter 3
At which layer of the OSI model does multiplexing take place?
- Layer 1
- Layer 2
- Layer 3
- Layer 4
Which command can be used to view the cable type that is attached to a serial interface?
- Router(config)# show interfaces
- Router(config)# show controllers
- Router(config)# show ip interface
- Router(config)# show ip interface brief
Which field marks the beginning and end of an HDLC frame?
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, line protocol is down
- Serial 0/0/0 is down, line protocol is down
- Serial 0/0/0 is up (looped)
- Serial 0/0/0 is up (disabled)
- Serial 0/0/0 is administratively down, line protocol is down
Which is an advantage of using PPP on a serial link instead of HDLC?
- option for authentication
- higher speed transmission
- fixed-size frames
- option for session establishment
What are three components of PPP? (Choose three.)
- HDLC-like framing
How does PPP interface with different network layer protocols?
- by using separate NCPs
- by negotiating with the network layer handler
- by encoding the information field in the PPP frame
- by specifying the protocol during link establishment through LCP
Which address is used in the Address field of a PPP frame?
- a single byte of binary 00000000
- a single byte of binary 10101010
- a single byte of binary 11111111
- the IP address of the serial interface
Which three physical layer interfaces support PPP? (Choose three.)
- asynchronous serial
- synchronous serial
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-control frames
- link-establishment frames
Which protocol will terminate the PPP link after the exchange of data is complete?
During a PPP session establishment phase, which two messages are sent by the requested party if the options are not acceptable? (Choose two.)
Which three statements are true about PPP? (Choose three.)
- PPP can use synchronous and asynchronous circuits.
- PPP can only be used between two Cisco devices.
- PPP carries packets from several network layer protocols in LCPs.
- PPP uses LCPs to establish, configure, and test the data link connection.
- PPP uses LCPs to agree on format options such as authentication, compression, and error detection.
Which PPP option can detect links that are in a looped-back condition?
- Magic Number
When configuring Multilink PPP, where is the IP address for the multilink bundle configured?
- on a physical serial interface
- on a subinterface
- on a multilink interface
- on a physical Ethernet interface
Refer to the exhibit. Which statement describes the status of the PPP connection?
- Only the link-establishment phase completed successfully.
- Only the network-layer phase completed successfully.
- Neither the link-establishment phase nor the network-layer phase completed successfully.
- Both the link-establishment and network-layer phase completed successfully.
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 usernames do not match.
- The passwords do not match.
- The passwords should be longer than 8 characters.
- The interface IP addresses are in different subnets.
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 plain text passwords are needed to simulate login at the remote host
- when a network administrator prefers it because of ease of configuration
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.)
- establishes identities with a two-way handshake
- uses a three-way authentication periodically during the session to reconfirm identities
- control by the remote host of the frequency and timing of login events
- transmits login information in encrypted format
- uses an unpredictable variable challenge value to prevent playback attacks
- makes authorized network administrator intervention a requirement to establish each session
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.
- A PPP session was successfully established.
- Both PAP and CHAP authentication were attempted.
- The debug output is from router R2.
Match the phases of establishing a PPP session in the correct order. (Not all options are used.)
Match the PPP option with the correct description. (Not all options are used.)
Match the steps to the PPP CHAP authentication process sequence. (Not all options are used.)