CCNA Exploration 4 Final
Here we are, folks, it’s the final exam of the Cisco Certified Network Associate’s Exploration curriculum, and we hope you’ve been keeping your nose in a book because this is a big one! Think you have what it takes to get a decent result in the final exam? Let’s find out once and for all!
- 1.
Which of the following describes the roles of devices in a WAN? (Choose three.)
- A.
A CSU/DSU terminates a digital local loop.
- B.
A modem terminates a digital local loop
- C.
A CSU/DSU terminates an analog local loop.
- D.
A modem terminates an analog local loop.
- E.
A router is commonly considered a DTE device.
Correct Answer(s)
A. A CSU/DSU terminates a digital local loop.
D. A modem terminates an analog local loop.
E. A router is commonly considered a DTE device.Explanation
A CSU/DSU terminates a digital local loop, which means it connects the customer's equipment to the service provider's network. A modem terminates an analog local loop, converting analog signals from the customer's equipment to digital signals that can be transmitted over the WAN. A router is commonly considered a DTE (Data Terminal Equipment) device, which means it is responsible for generating or receiving data and controlling the flow of data over the network.Rate this question:
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- 2.
What value in the address field of a Frame Relay header identifies the destination of the frame?
- A.
CIR
- B.
DE
- C.
DLCI
- D.
ISDN
- E.
FRAD
Correct Answer
C. DLCIExplanation
The DLCI (Data Link Connection Identifier) value in the address field of a Frame Relay header identifies the destination of the frame. DLCI is a unique identifier assigned to each virtual circuit in a Frame Relay network, allowing the network to determine the correct destination for incoming frames.Rate this question:
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- 3.
The serial PPP link between the Left and Right routers is configured as shown in the diagram. Which configuration issue explains why the link is unable to establish a PPP session?
- A.
The IP addresses must be on different subnets.
- B.
The usernames are misconfigured.
- C.
The passwords must be different for the CHAP authentication
- D.
The clock rate must be 56000.
- E.
The clock rate is configured on the wrong end of the link.
Correct Answer
B. The usernames are misconfigured. -
- 4.
The output of the show interfaces serial 0/0 command for a frame-relay connection indicates that the serial line is up but the line protocol is down. What are possible causes for this? (Choose two.)
- A.
There is an LMI-type mismatch between the Frame Relay switch and the router.
- B.
There is no clock present on the serial interface.
- C.
The interface is shut down.
- D.
RARP is not functioning on the router
- E.
The cable is disconnected.
Correct Answer(s)
A. There is an LMI-type mismatch between the Frame Relay switch and the router.
E. The cable is disconnected.Explanation
The output of the show interfaces serial 0/0 command indicates that although the physical connection is established (line is up), the protocol used for communication (line protocol) is not functioning properly (line protocol is down). This can be caused by an LMI-type mismatch between the Frame Relay switch and the router, where they are using different LMI types for signaling. Another possible cause is that the cable is disconnected, resulting in the line protocol being down.Rate this question:
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- 5.
Which statements are correct about the point in the network where the responsibility of the service provider ends? (Choose three.)
- A.
The International point is on the customer side of the network terminating unit(NTU).
- B.
The United States point is at the interface of the customer-provided equipment and the local loop.
- C.
The responsibility for this point is controlled by IANA.
- D.
The point is called the demarcation point.
- E.
The point is typically located at the service provider's central office.
Correct Answer(s)
A. The International point is on the customer side of the network terminating unit(NTU).
B. The United States point is at the interface of the customer-provided equipment and the local loop.
D. The point is called the demarcation point.Explanation
The correct answer is that the International point is on the customer side of the network terminating unit (NTU), the United States point is at the interface of the customer-provided equipment and the local loop, and the point is called the demarcation point. These statements describe the different locations where the responsibility of the service provider ends. The International point refers to the point on the customer side of the NTU, which marks the end of the service provider's responsibility. The United States point is where the customer-provided equipment connects to the local loop, indicating another point where the service provider's responsibility ends. Finally, the demarcation point is the term used to describe the specific location where the service provider's responsibility ends.Rate this question:
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- 6.
While prototyping an internetwork in the corporate lab, a network administrator is testing a serial link between serial 0/0 interfaces on two routers. The labels on the serial cable ends have been damaged and are unreadable. What command can be issued to determine which router is connected to the DCE cable end?
- A.
Show interfaces serial 0/0
- B.
Show version
- C.
Show controllers serial 0/0
- D.
Show protocols serial 0/0
- E.
Show status serial 0/0
Correct Answer
C. Show controllers serial 0/0Explanation
The command "show controllers serial 0/0" can be issued to determine which router is connected to the DCE cable end. This command will display information about the serial interface, including the cable type and whether it is acting as a DCE or DTE device. By checking this information, the network administrator can identify which router is connected to the DCE cable end.Rate this question:
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- 7.
A network technician determines DHCP clients are not working properly. The clients are receiving IP configuration information from a DHCP server configured on the router but cannot access the Internet. From the output in the graphic, what is the most likely problem?
- A.
The DHCP server service is not enabled.
- B.
The inside interface for DCHP is not defined
- C.
The DHCP pool is not bound to the interface.
- D.
The pool does not have a default router defined for the clients.
- E.
All the host addresses have been excluded from the DHCP pool.
Correct Answer
C. The DHCP pool is not bound to the interface.Explanation
The most likely problem is that the DHCP pool is not bound to the interface. This means that the DHCP server is not properly assigning IP configuration information to the clients because it is not associated with the correct interface. As a result, the clients are unable to access the internet even though they are receiving IP configuration information from the DHCP server.Rate this question:
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- 8.
A technician enters the interface serial 0/0.1 multipoint command when configuring a router. What effect will the multipoint keyword have in this configuration? (Choose two.)
- A.
Split-horizon issues will need to be resolved for this network if RIP is the routing protocol.
- B.
A subinterface will be defined for each PVC.
- C.
All the participating interfaces of remote routers will be configured in the same subnet.
- D.
A single DLCI will be used to define all the PVCs to the remote routers.
- E.
An IP address will need to be configured on the main interface.
Correct Answer(s)
A. Split-horizon issues will need to be resolved for this network if RIP is the routing protocol.
C. All the participating interfaces of remote routers will be configured in the same subnet.Explanation
The multipoint keyword in the "interface serial 0/0.1 multipoint" command indicates that the interface is configured as a multipoint interface. This means that the router will be connected to multiple remote routers using different PVCs (Permanent Virtual Circuits) on the same physical interface.
The first effect of using the multipoint keyword is that split-horizon issues will need to be resolved if RIP (Routing Information Protocol) is the routing protocol. Split-horizon is a mechanism that prevents a router from advertising a route back out of the same interface it was received on, in order to avoid routing loops. In a multipoint configuration, split-horizon needs to be carefully configured to allow proper routing updates.
The second effect is that all the participating interfaces of remote routers will be configured in the same subnet. This means that all the remote routers connected to the multipoint interface will have their interfaces configured with IP addresses from the same subnet, allowing them to communicate with each other.Rate this question:
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- 9.
When configuring a Frame Relay connection, when should a static Frame Relay map be used? (Choose two.)
- A.
When the remote router is a non-Cisco router
- B.
when the remote router does not support Inverse ARP
- C.
When the local router is using IOS Release 11.1 or earlier
- D.
When broadcast traffic and multicast traffic over the PVC must be controlled
- E.
When globally significant rather than locally significant DLCIs are being used
Correct Answer(s)
B. when the remote router does not support Inverse ARP
D. When broadcast traffic and multicast traffic over the PVC must be controlledExplanation
A static Frame Relay map should be used when the remote router does not support Inverse ARP. Inverse ARP is a protocol that allows a router to discover the IP address of a remote device connected to a Frame Relay network. If the remote router does not support Inverse ARP, a static Frame Relay map is necessary to manually configure the mapping between the DLCI and the IP address of the remote device.
A static Frame Relay map should also be used when broadcast traffic and multicast traffic over the PVC must be controlled. By using a static Frame Relay map, the router can specify which DLCIs are allowed to receive broadcast and multicast traffic, ensuring that only the desired PVCs receive this type of traffic.Rate this question:
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- 10.
Which router command would be used to associate a Layer 2 address with the corresponding Layer 3 address in the internetwork in the diagram?
- A.
RouterA(config-if)#frame-relay pvc 100 192.168.15.2
- B.
RouterA(config-if)#dialer-map ip 192.168.15.1 100 broadcast
- C.
RouterA(config-if)#frame-relay map ip 192.168.15.2 100 broadcast
- D.
RouterA (config-if)#dialer-map 192.168.15.1 101 serial 0 broadcast
- E.
RouterA (config-if)#frame-relay dlci 101 192.168.15.1 broadcast
Correct Answer
C. RouterA(config-if)#frame-relay map ip 192.168.15.2 100 broadcastExplanation
The correct answer is RouterA(config-if)#frame-relay map ip 192.168.15.2 100 broadcast. This command is used to associate a Layer 2 address with the corresponding Layer 3 address in the internetwork. By using the "frame-relay map" command, the router is able to map the Layer 2 DLCI (Data Link Connection Identifier) 100 to the Layer 3 IP address 192.168.15.2. The "broadcast" keyword indicates that the router should forward broadcast traffic to this DLCI.Rate this question:
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- 11.
Which of the following ISDN protocols is responsible for call setup and call teardown?
- A.
• ITU-T Q.921
- B.
• ITU-T Q.931
- C.
• ITU-T I.430
- D.
• ITU-T I.431
Correct Answer
A. • ITU-T Q.921Explanation
ITU-T Q.921 is responsible for call setup and call teardown in ISDN protocols.Rate this question:
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- 12.
What are two ways to resolve split-horizon issues in a Frame Relay network? (Choose two.)
- A.
Create a full-mesh topology
- B.
Disable Inverse ARP
- C.
Use point-to-point subinterfaces
- D.
Use multipoint subinterfaces
- E.
Remove the broadcast keyword from the frame-relay map command
Correct Answer(s)
A. Create a full-mesh topology
C. Use point-to-point subinterfacesExplanation
To resolve split-horizon issues in a Frame Relay network, creating a full-mesh topology can be done. This means establishing direct connections between all the network devices, allowing them to communicate without any restrictions. Additionally, using point-to-point subinterfaces can also help resolve split-horizon problems. This involves dividing the main interface into multiple subinterfaces, each representing a separate point-to-point connection, thus eliminating the split-horizon issue.Rate this question:
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- 13.
What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco 806 broadband router?
- A.
Defines which addresses are allowed out of the router
- B.
Defines which addresses are allowed into the router
- C.
Defines which addresses can be translated
- D.
Defines which addresses are assigned to a NAT pool
Correct Answer
B. Defines which addresses are allowed into the routerExplanation
The command marked with an arrow in the partial configuration output of a Cisco 806 broadband router is used to define which addresses are allowed into the router. This command determines the source addresses that are permitted to access the router and its services.Rate this question:
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- 14.
system administrator is unable to ping the Serial0/0 interface of RouterB from RouterA. During the troubleshooting process, the following facts are established: - IP addressing and subnet masks are correct. - RouterA is a Cisco router and RouterB is a router from another vendor. - RouterA is configured with the default encapsulation. - The serial interfaces on both routers are up. - The protocol is downWhat should the administrator do to solve the problem? on the serial interfaces of both routers.
- A.
Add a clock rate on RouterA.
- B.
Enable the serial interface on RouterB.
- C.
Change the encapsulation on both routers to PPP.
- D.
Connect the serial cable to the correct interface on RouterB.
- E.
Use the correct serial cable to attach the CSU/DSU to RouterB.
Correct Answer
C. Change the encapsulation on both routers to PPP.Explanation
The administrator should change the encapsulation on both routers to PPP. Since RouterA is a Cisco router and RouterB is from another vendor, they may be using different encapsulation protocols. By changing the encapsulation on both routers to PPP, they will be using a standardized protocol that is compatible with both routers and should allow them to establish a connection.Rate this question:
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- 15.
An ISDN circuit from a branch office is remaining connected to the regional office. A network administrator determines a user has initiated a continuous ping from a desktop computer to the regional office. Which configuration change would allow the ISDN circuit to disconnect during any attempts to ping, while otherwise functioning properly?
- A.
Change DDR from legacy to dialer profiles
- B.
Remove the dialer list statement from the configuration
- C.
Change the dialer list to exclude ICMP as interesting
- D.
Disable inverse ARP
Correct Answer
C. Change the dialer list to exclude ICMP as interestingExplanation
Changing the dialer list to exclude ICMP as interesting would allow the ISDN circuit to disconnect during any attempts to ping while otherwise functioning properly. This means that ICMP traffic, which includes ping requests, would not be considered "interesting" and would not trigger the ISDN circuit to remain connected. This configuration change would effectively disconnect the ISDN circuit during ping attempts.Rate this question:
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- 16.
Below is a list of DDR steps. Which of the following identifies the proper order of DDR? 1 - dial number is looked up 2 - interesting traffic triggers DDR 3 - route to destination is determined 4 - call is made
- A.
1,2,3,4
- B.
1,3,2,4
- C.
2,3,1,4
- D.
2,1,3,4
- E.
3,2,1,4
Correct Answer
E. 3,2,1,4Explanation
First, the route to the destination is determined (step 3). Then, interesting traffic triggers DDR (step 2). After that, the dial number is looked up (step 1). Finally, the call is made (step 4). Therefore, the proper order of DDR is 3, 2, 1, 4.Rate this question:
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- 17.
Which protocol should be chosen to support WAN connectivity in a multi-vendor system and provide strong security through authentication?
- A.
Frame Relay
- B.
HDLC with encryption
- C.
HDLC with CHAP
- D.
PPP with PAP
- E.
PPP with CHAP
Correct Answer
E. PPP with CHAPExplanation
PPP with CHAP (Challenge Handshake Authentication Protocol) should be chosen to support WAN connectivity in a multi-vendor system and provide strong security through authentication. CHAP is a secure authentication protocol that uses a three-way handshake process to verify the identity of the remote device. It provides mutual authentication and protects against replay attacks. PPP (Point-to-Point Protocol) is a widely used protocol for establishing a direct connection between two nodes, and when combined with CHAP, it ensures secure authentication over the WAN.Rate this question:
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- 18.
Which of the following are valid steps for a basic ISDN BRI configuration? (Choose two.)
- A.
Create subinterfaces
- B.
Define the LMI type
- C.
Set the SPIDs if required by the ISDN switch
- D.
Set the interface DLCI
- E.
Set the switch type
Correct Answer(s)
C. Set the SPIDs if required by the ISDN switch
E. Set the switch typeExplanation
The correct answer is to set the SPIDs if required by the ISDN switch and to set the switch type. These two steps are necessary for a basic ISDN BRI configuration. The SPIDs (Service Profile Identifiers) are unique identifiers that are assigned by the ISDN switch to the ISDN devices. Setting the SPIDs is important to establish a connection with the ISDN switch. Additionally, setting the switch type is crucial as it determines the signaling and protocol used for communication between the ISDN devices and the ISDN switch.Rate this question:
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- 19.
A branch office reports excessive connect time charges for an ISDN circuit used to connect to the regional office. Upon investigation of this issue, it is discovered that when an ISDN connection is initiated to the regional office it remains connected for an excessive amount of time. Which of the following configuration changes could be made to DDR on the router to reduce these connect time charges?
- A.
Use PPP multilink
- B.
Lower idle timer setting
- C.
Use CHAP authentication
- D.
Change DDR from legacy to dialer profiles
Correct Answer
D. Change DDR from legacy to dialer profilesExplanation
Changing DDR from legacy to dialer profiles could potentially reduce connect time charges for the ISDN circuit. This change would allow for more efficient and optimized management of the dial-up connections, potentially reducing the amount of time the connection remains active and therefore reducing charges.Rate this question:
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- 20.
A network administrator is having difficulty in establishing a serial link between a Cisco router and a router from another vendor. Both routers are configured for HDLC encapsulation. Which statements are true regarding this configuration? (Choose two.)
- A.
The Cisco HDLC frame uses a proprietary "Type" field that may not be compatible with equipment of other vendors.
- B.
HDLC requires a clock rate to be configured on the routers at both ends of the serial link.
- C.
PPP encapsulation is recommended for serial links between equipment from multiple vendors.
- D.
Usernames must be configured at both ends of the HDLC serial link.
- E.
The HDLC vendor type must be enabled on the Cisco router.
Correct Answer(s)
A. The Cisco HDLC frame uses a proprietary "Type" field that may not be compatible with equipment of other vendors.
C. PPP encapsulation is recommended for serial links between equipment from multiple vendors.Explanation
The first statement is true because the Cisco HDLC frame uses a proprietary "Type" field that may not be compatible with equipment from other vendors. This means that the Cisco router may not be able to establish a serial link with the router from another vendor.
The second statement is also true because HDLC requires a clock rate to be configured on the routers at both ends of the serial link. This clock rate is necessary for synchronization between the routers.
PPP encapsulation is recommended for serial links between equipment from multiple vendors, but this statement is not mentioned in the question so it cannot be considered as a correct answer.
The last two statements, usernames must be configured at both ends of the HDLC serial link and the HDLC vendor type must be enabled on the Cisco router, are not mentioned in the question and cannot be considered as correct answers.Rate this question:
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