ActualTests.Cisco.640-802.Exam.Q.and.A.08.15.08-DDU (1130589), страница 77
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The output from the "show interface" command on both routersshows that the serial interface is up, line protocol is down. Given the partial outputfor the show running-config in the exhibit, what is the most likely cause of thisproblem?Actualtests.com - The Power of Knowing640-802A. The serial cable is bad.B. The MTU is incorrectly configured.C. The IP addresses are not in the same subnet.D. The Layer 2 framing is misconfigured.E. None of the above.Answer: DExplanation:HDLC and PPP are layer 2 protocols. HDLC is actually the default protocol on all Ciscoserial interfaces. If you do a show running-config on a Cisco router, your serial interfaces(by default) won't have any encapsulation.
This is because they are configured to thedefault of HDLC. If you do a show interface serial 0/0, you'll see that you are runningHDLC. This is the case with router Certkiller 2, as the default encapsulation is used.In router Certkiller 1, we see that the serial interface has been set to use PPP. Since bothsides of a point to point circuit must match, the layer 2 framing is the most likely cause ofthe problem.QUESTION 681:Network Topology Exhibit:Configuration exhibit:Actualtests.com - The Power of Knowing640-802You work as a network technician at Certkiller .com. Study the exhibits carefully.The Frame-Relay network in the diagram is not functioning properly.
Based on theinformation shown above, what is the cause of the problem?A. The S3 interface of the Certkiller 2 router has been configured with the "frame relayencapsulation ietf" commandB. The Frame-relay map statement in the Certkiller 3 router for the PVC to Certkiller 2 isnot correctC. The Certkiller 1 router has the wrong LMI type configuredD. Inverse ARP is providing the wrong PVC information to the Certkiller 1 RouterE. The IP Address on the serial interface of the Certkiller 3 router is configuredincorrectlyF.
None of the aboveAnswer: BExplanation:On serial 3 of Certkiller 3 we can see that there are 2 PVC's defined, but only one of themis working and is shown as active. The frame relay map that was used to specify DLCI509 was incorrect. Incorrect DLCI assignments that are configured in routers normallyshow up as "deleted" in the frame relay maps.QUESTION 682:The following output was displayed on a Certkiller router:Based on the information shown above, what is the meaning of the term "dynamic"as displayed in the output of the show frame-relay map command shown?Actualtests.com - The Power of Knowing640-802A.
The DLCI 100 will be dynamically changed as required to adapt to changes in theFrame Relay cloudB. The DLIC 100 was dynamically allocated by the routerC. The mapping between DLCI 100 and the end station IP Address 172.16.3.1 waslearned through inverse ARPD. The Scenario0/0 interface is passing trafficE. The Serial0/0 interface acquired the IP address 172.16.3.1 from a DHCP serverF. None of the aboveAnswer: CExplanation:Inverse Address Resolution Protocol (Inverse ARP) was developed to provide amechanism for dynamic DLCI to Layer 3 address maps.
Inverse ARP works much thesame way Address Resolution Protocol (ARP) works on a LAN. However, with ARP, thedevice knows the Layer 3 IP address and needs to know the remote data link MACaddress. With Inverse ARP, the router knows the Layer 2 address which is the DLCI, butneeds to know the remote Layer 3 IP address.When using dynamic address mapping, Inverse ARP requests a next-hop protocoladdress for each active PVC. Once the requesting router receives an Inverse ARPresponse, it updates its DLCI-to-Layer 3 address mapping table. Dynamic addressmapping is enabled by default for all protocols enabled on a physical interface.
If theFrame Relay environment supports LMI autosensing and Inverse ARP, dynamic addressmapping takes place automatically. Therefore, no static address mapping is required.QUESTION 683:The command "frame-relay map ip 10.121.16.8 102 broadcast" was entered on aCertkiller FR router. Which of the following statements is true concerning thiscommand?A.
The command is required for all frame relay configurationsB. The broadcast option allows packets, such as RIP updates to be forwarded across thePVCC. This command should be executed from the global configure modeD. 102 is the remote DLCI that will receive the informationE. The IP Address 10.121.16.8 is the local router port used to forward dataF. None of the aboveAnswer: BExplanation:The broadcast keyword is commonly used with the frame-relay map command.
Thebroadcast keyword provides two functions. First, it forwards broadcasts whenmulticasting is not enabled and secondly, it simplifies the configuration of OSPF forActualtests.com - The Power of Knowing640-802nonbroadcast networks that use Frame Relay.The broadcast keyword might also be required for routing protocols such as RIP thatdepend on regular routing table updates. This is especially true when the router at theremote end is waiting for a routing update packet to arrive before adding the route.QUESTION 684:Many Certkiller locations are connected via Frame Relay, and the default networktypes are being used. By default, a Frame Relay WAN is classified as what type ofphysical network?A. Point-To-PointB. Nonbroadcast multi-accessC.
Broadcast Point-To-MultipointD. Nonbroadcast multipointE. Broadcast multi-accessF. Broadcast multi-accessG. None of the aboveAnswer: BQUESTION 685:Three Certkiller routers are connected as shown below:Here, serial 0/0 on Certkiller 1 is configured as a multipoint interface tocommunicate with Certkiller 2 and Certkiller 3 in this hub-and-spoke Frame Relaytopology.
While testing this configuration, a technician notes that pings aresuccessful from hosts on the 172.16.1.0/24 network to hosts on both the 172.16.2.0/25and 172.16.2.128/25 networks. However, pings between hosts on the 172.16.2.0/25Actualtests.com - The Power of Knowing640-802and 172.16.2.128/25 networks are not successful. Of the following choices, whatcould explain this connectivity problem?A. The 172.16.3.0/29 network used on the Frame Relay links is creating a discontiguousnetwork between the Certkiller 2 and Certkiller 3 router subnetworksB. The 172.16.2.0/25 and 172.16.2.128/25 networks are overlapping networks that can beseen by Certkiller 1 but not between Certkiller 2 and Certkiller 3C. The ip subnet-zero command has been issued on the Certkiller 1 routerD.
Split Horizon is preventing Certkiller 2 from learning about the Certkiller 3 networksand Certkiller 3 from learning about the Certkiller 2 networksE. The RIP v2 dynamic routing protocol can't be used across Frame Relay networkF. None of the aboveAnswer: DExplanation:The problem in this situation is related to split horizon, which reduces incorrect routinginformation and routing overhead in a distance-vector network by enforcing the rule thatinformation cannot be sent back in the direction from which it was received.
In otherwords, the routing protocol differentiates which interface a network route was learned on,and once it determines this, it won't advertise the route back out of that same interface.in a spoke and hub Frame Relay topology, the Frame Relay interface for the hub routermust have split-horizon processing disabled. Otherwise, the spoke routers never receiveeach other's routes.QUESTION 686:You are implementing a new frame relay network to provide connectivity betweenyou offices. To do this, you set up the frame relay network using point-to-pointsubinterfaces.Which of the following does NOT need to 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.Answer: CExplanation:When using point to point subinterfaces in a frame relay network, the subinterfaces willeach have their own IP addresses and will each be contained within their own IP subnet.The physical interface does not require an IP address.Incorrect Answers:Actualtests.com - The Power of Knowing640-802A.
The physical interface will need to be configured with a layer two encapsulation type,so in this case it must be frame relay.B. The subinterfaces will have the local DLCI assigned to each one, using the"frame-relay interface-dlci" command for each of the subinterfaces.D. Each subinterface should be configured as a point to point network type.QUESTION 687:It has become necessary to configure an existing serial interface to accept a secondFrame Relay virtual circuit. Which of the following procedures are required toaccomplish this task? (Choose three.)A. Encapsulate the physical interface with multipoint PPP.B.
Configure static Frame Relay map entries for each subinterface network.C. Disable split horizon to prevent routing loops between the subinterface networks.D. Remove the IP address from the physical interface.E. Create the virtual interfaces with the interface command.F. Configure each subinterface with its own IP address.Answer: D, E, FExplanation:Normally, when only one logical virtual circuit (PVC) is assigned to a router it is placedon the physical serial interface.
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