wide area networks




1).
When setting up Frame Relay for point-to-point subinterfaces, which of the following must not be configured?
A   The Frame Relay encapsulation on the physical interface   
B   The local DLCI on each subinterface   
C   An IP address on the physical interface   
D   The subinterface type as point-to-point   
ANS: C - An IP address on the physical interface

It is very important to remember when studying the CCNA exam objectives, and when configuring Frame Relay with point-to-point subinterfaces, that you do not put an IP address on the physical interface.

2).
Which command will display the CHAP authentication process as it occurs between two routers in the network?
A   show chap authentication   
B   show interface serial 0   
C   debug ppp authentication   
D   debug chap authentication   
ANS: C - debug ppp authentication

The command debug ppp authentication will show you the authentication process that PPP uses between point-to-point connections.

3).
The Acme Corporation is implementing dial-up services to enable remote-office employees to connect to the local network. The company uses multiple routed protocols, needs authentication of users connecting to the network, and since some calls will be long distance, needs callback support. Which of the following protocols is the best choice for these remote services?
A   802.1   
B   Frame Relay   
C   HDLC   
D   PPP   
E   PAP   
ANS: E - PAP

PPP is your only option, as HDLC and Frame Relay do not support these types of business requirements. PPP provides dynamic addressing, authentication using PAP or CHAP, and callback services.

4).
You need to configure a router for a Frame Relay connection to a non-Cisco router. Which of the following commands will prepare the WAN interface of the router for this connection?
A   Router(config-if)#encapsulation frame-relay q933a   
B   Router(config-if)#encapsulation frame-relay ansi   
C   Router(config-if)#encapsulation frame-relay ietf   
D   Router(config-if)#encapsulation frame-relay cisco   
ANS: C - Router(config-if)#encapsulation frame-relay ietf

If you have a Cisco router on one side of a Frame Relay network and a non-Cisco router on the other side, you would need to use the Frame Relay encapsulation type of IETF. The default is Cisco encapsulation, which means that a Cisco router must be on both sides of the Frame Relay network.

5).
Which WAN encapsulations can be configured on an asynchronous serial connection?
  1. PPP
  2. ATM
  3. HDLC
  4. SDLC
  5. Frame Relay
A   1 and 2   
B   2 and 4   
C   3, 4 and 5   
D   All of the above   
ANS: A - 1 and 2

Please do not freak out because ATM is an answer to this question. ATM is not covered in depth on the CCNA exam. PPP is mostly used for dial-up (async) services, but ATM could be used as well, though it typically is not used anymore since PPP is so efficient.

6).
Which encapsulations can be configured on a serial interface?
  1. Ethernet
  2. Token Ring
  3. HDLC
  4. Frame Relay
    1. PPP
A   1 and 4   
B   2 only   
C   3, 4 and 5   
D   All of the above   
ANS: C - 3, 4 and 5

Ethernet and Token Ring are LAN technologies and cannot be configured on a serial interface. PPP, HDLC, and Frame Relay are layer 2 WAN technologies that are typically configured on a serial interface.

7).
Suppose that you have a customer who has a central HQ and six branch offices. They anticipate adding six more branches in the near future. They wish to implement a WAN technology that will allow the branches to economically connect to HQ and you have no free ports on the HQ router. Which of the following would you recommend?
A   PPP   
B   HDLC   
C   Frame Relay   
D   ISDN   
ANS: C - Frame Relay

The key is "there are no free ports" on your router. Only Frame Relay can provide a connection to multiple locations with one interface, and in an economical manner no less.

8).
Which of the following command options are displayed when you use the Router# show frame-relay ? command?
  1. dlci
  2. neighbors
  3. lmi
  4. pvc
  5. map
A   1 only   
B   2 and 4   
C   3, 4 and 5   
D   All of the above   
ANS: C - 3, 4 and 5

The show frame-relay ? command provides many options, but the options available in this question are lmipvc, and map.

9).
In which of the following technologies is the term HFC used?
A   DSL   
B   PPPoE   
C   Frame Relay   
D   Dedicated T1   
ANS: D - Dedicated T1

In a modern network, hybrid fibre-coaxial (HFC) is a telecommunications industry term for a network that incorporates both optical fiber and coaxial cable to create a broadband network.

10).
A default Frame Relay WAN is classified as what type of physical network?
A   Point-to-point   
B   Broadcast multi-access   
C   Non-broadcast multi-access   
D   Non-broadcast multipoint   
ANS: C - Non-broadcast multi-access

Frame Relay, by default, is a non-broadcast multi-access (NBMA) network, which means that broadcasts, such as RIP updates, will not be forwarded across the link by default.

11).
Which of the following describes the creation of private networks across the Internet, enabling privacy and tunneling of non-TCP/IP protocols?
A   HDLC   
B   Cable   
C   VPN   
D   IPSec   
E   xDSL   
ANS: C - VPN

A allows the creation of private networks across the Internet, enabling privacy and tunneling of non-TCP/IP protocols. A VPN can be set up across any type of link.

12).
Which of the following describes an industry-wide standard suite of protocols and algorithms that allows for secure data transmission over an IP-based network that functions at the layer 3 Network layer of the OSI model?
A   HDLC   
B   Cable   
C   VPN   
D   IPSec   
E   xDSL   
ANS: E - xDSL

IPSec is an industry-wide standard suite of protocols and algorithms that allows for secure data transmission over an IP-based network that functions at the layer 3 Network layer of the OSI model.

13).
Which of the following uses ATM as the Data Link layer protocol that's terminated at what's known as the DSLAM?
A   DSL   
B   PPPoE   
C   Frame Relay   
D   Dedicated T1   
E   Wireless   
ANS: A - DSL

ATM is the Data-Link layer protocol that's typically used over the DSL layer 1 connection from the CPE and terminated at what's known as the DSLAM-an ATM switch that contains DSL interface cards, or ATU-Cs.

14).
When a router is connected to a Frame Relay WAN link using a serial DTE interface, how is the clock rate determined?
A   Supplied by the CSU/DSU   
B   By the far end router   
C   By the clock rate command   
D   By the Physical layer bit stream timing   
ANS: A - Supplied by the CSU/DSU

Clocking on a serial interface is always provided by the CSU/DSU (DCE device). However, if you do not have a CSU/DSU in your nonproduction test environment, then you need to supply clocking with the clock rate command on the serial interface of the router with the DCE cable attached.

15).
Which command is required for connectivity in a Frame Relay network if Inverse ARP is not operational?
A   frame-relay arp   
B   frame-relay map   
C   frame-relay interface-dci   
D   frame-relay lmi-type   
ANS: B - frame-relay map

If you have a router in your Frame Relay network that does not support IARP, you must create Frame Relay maps on your router, which provide known DLCI-to-IP address mappings.

16).
How should a router that is being used in a Frame Relay network be configured to keep split horizon issues from preventing routing updates?
A   Configure a separate subinterface for each PVC with a unique DLCI and subnet assigned to the subinterface.   
B   Configure each Frame Relay circuit as a point-to-point line to support multicast and broadcast traffic.   
C   Configure many subinterfaces in the same subnet.   
D   Configure a single subinterface to establish multiple PVC connections to multiple remote router interfaces.   
ANS: A - Configure a separate subinterface for each PVC with a unique DLCI and subnet assigned to the subinterface.

If you have a serial port configured with multiple DLCIs connected to multiple remote sites, split horizon rules, stop route updates received on an interface from being sent out the same interface. By creating subinterfaces for each PVC, you can avoid the split horizon issues when using Frame Relay.

17).
Which of the following encapsulates PPP frames in Ethernet frames and uses common PPP features like authentication, encryption, and compression?
A   PPP   
B   PPPoA   
C   PPPoE   
D   Token Ring   
ANS: C - PPPoE

PPPoE encapsulates PPP frames in Ethernet frames and uses common PPP features like authentication, encryption, and compression. PPPoA is used for ATM.