ActualTests.Cisco.640-802.Exam.Q.and.A.08.15.08-DDU (1130589), страница 78
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To accept a second PVC, subinterfaces must be created,with each PVC using its own logical interface as shown in the example below:interface serial 0encapsulation frame-relayinterface serial 0.1 point-to-pointip address 10.0.1.1 255.255.255.0frame-relay interface-dlci 142interface serial 0.2 multipointip address 10.0.2.1 255.255.255.0frame-relay map 10.0.2.2 118In this example, two virtual circuits are used (one pt-pt and one point-multipoint), eachwith its own IP address. Note that the physical serial 0 interface was not assigned an IPaddress.QUESTION 688:You are a technician at Certkiller .
Your newly appointed Certkiller trainee is settingup a new frame relay connection to a remote branch and wants to know what thevalid options for frame relay LMI types are.What would your reply be? (Choose all that apply.)Actualtests.com - The Power of Knowing640-802A.
EIA/TIAB. Q.932C. Q.933 AD. IEEEE. IETFF. CiscoG. ANSIAnswer: C, F, GExplanation:The following describe the various frame relay LMI options:Name Document IOS LMI-Type* Cisco Proprietary cisco* ANSI T1.617 Annex D ansi* ITU Q.933.
Annex A q.933aYou can set one of three types of LMIs on our devices: ANSI T1.617 Annex D, Cisco,and ITU-T Q.933 AnnexA. To do so, use the following commands beginning in interfaceconfiguration mode:Reference:CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN1-58720-083-X) Page 382QUESTION 689:How should router CK1 , which will be used in the Certkiller Frame Relay network,be configured to avoid split horizon issues from preventing routing updates?A.
Configure a single sub-interface to establish multiple PVC connections to multipleremote router interfaces.B. Configure a separate sub-interface for each PVC with a unique DLCI and subnetassigned to the sub-interface.C. Configure many sub-interfaces on the same subnet.D. Configure each Frame Relay circuit as a point-to-point line to support multicast andbroadcast traffic.E.
None of the aboveActualtests.com - The Power of Knowing640-802Answer: BExplanation:Point-To-Point Subinterfaces:The concept of subinterfaces was originally created in order to better handle issuescaused by split-horizon over Non-Broadcast Multiple Access (NBMA) networks (e.g.frame relay, X.25) and distance-vector based routing protocols (e.g. IPX RIP/SAP,AppleTalk). Split-horizon dictates that a routing update received on an interface cannotbe retransmitted out onto the same interface. This rule holds even if the routing updatewas received on one frame relay PVC and destined to retransmit out onto another framerelay PVC.
Referring to figure 2, this would mean that sites B and C can exchangerouting information with site A, but would not be able to exchange routing informationwith each other. Split-horizon does not allow Site A to send routing updates receivedfrom Site B on to Site C and vice versa.Note: For TCP/IP, Cisco routers can disable split-horizon limitations on all frame relayinterfaces and multipoint subinterfaces and do this by default. However, split-horizoncannot be disabled for other protocols like IPX and AppleTalk.
These other protocolsmust use subinterfaces if dynamic routing is desired.By dividing the partially-meshed frame relay network into a number of virtual,point-to-point networks using subinterfaces, the split-horizon problem can be overcome.Each new point-to-point subnetwork is assigned its own network number. To the routedprotocol, each subnetwork now appears to be located on separate interfaces (Figure 3).Routing updates received from Site B on one logical point-to-point subinterface can beforwarded to site C on a separate logical interface without violating split horizon.QUESTION 690:Actualtests.com - The Power of Knowing640-802Router CK1 is being used in the Certkiller frame relay network.
When this framerelay router is connected to a WAN link using a serial DTE interface, how is theinterface clock rate determined?A. It is supplied by the far end router.B. It is supplied by the Layer 1 bit stream timing.C. It is supplied by the CSU/DSU.D. It is determined by the clock rate command.E. None of the aboveAnswer: CQUESTION 691:CK1 is a Cisco router was providing Frame Relay connectivity at a remote Certkillerbranch site.
This router was replaced with a different vendor's frame relay router.Connectivity is now down between the central and remote site. What is the mostlikely cause of the problem?A. Mismatched encapsulation typesB. Incorrect IP address mappingC. Mismatched LMI typesD. Incorrect DLCIE. None of the aboveAnswer: AQUESTION 692:The Certkiller frame relay network is shown below:Actualtests.com - The Power of Knowing640-802In this network, which statement describes DLCI 17?A. DLCI 17 is the Layer 2 address used by CK2 to describe a PVC to CK3 .B.
DLCI 17 describes the ISDN circuit between CK2 and CK3 .C. DLCI 17 describes a PVC on CK2 . It cannot be used on CK3 or CK1 .D. DLCI 17 describes the dial-up circuit from CK2 and CK3 to the service provider.E. None of the aboveAnswer: AExplanation:DLCI-Data Link Connection Identifier Bits: The DLCI serves to identify the virtualconnection so that the receiving end knows which information connection a framebelongs to. Note that this DLCI has only local significance.
Frame Relay is strictly aLayer 2 protocol suiteQUESTION 693:When configuring Frame Relay using point-to-point subinterfaces, which of thefollowing must not be configured? (Select one)A. The local DLCI on each subinterface of the Frame Relay.B. The Frame Relay encapsulation on the physical interface.C. An IP address on the physical interface.D. The subinterface type as point-to-pointE.
None of the aboveAnswer: CExplanation:Frame Relay does not require IP addresses on physical interfaces. A subnet address isusually assigned to each point-to-point connection. Therefore, only one DLCI can beconfigured per point-to-point subinterface. On point-to-point subinterfaces, thedestination is identified and configured with the frame-relay interface-dlci commandbeginning in interface configuration mode. When configured on a point-to-pointsubinterface, the command associates the selected point-to-point subinterface with aDLCI. The command also allows users to select the type of Frame Relay encapsulation tobe used on the specific VC. The command can be executed without specifying the FrameRelay encapsulation type to be used. By default, the Cisco Frame Relay encapsulationtype will be used.QUESTION 694:You are in the midst of configuring a router for a Frame Relay network.
WhatActualtests.com - The Power of Knowing640-802could you do to prevent split horizon problems? (Select all that apply)A. Configure a separate sub-interface for each PVC. Assign a unique DLCI and subnet toeach sub-interface.B. Configure each Frame Relay circuit as a point-to-point line to support multicast andbroadcast traffic.C. Configure one sub-interface to disperse into multiple PVC connections to multipleremote router interfaces.D. Configure as many as possible sub-interfaces on the same subnet.E. Use the "no ip split-horizons" command on the physical interface.Answer: A, EExplanation:The best solution is to configure subinterfaces for each virtual connection, because theindividual virtual circuits can be maintained and split horizon can remain on.Routingupdate information that is received through one subinterface can be propagated to othersubinterfaces, because each sub-interface is treated as a completely separate interface.Configuring Frame Relay subinterfaces ensures that a single physical interface is treatedas multiple virtual interfaces.
This capability allows you to overcome split horizon rulesso packets received on one virtual interface can be forwarded to another virtual interface,even if they are configured on the same physical interface. Another alternative to usingsub-interfaces is to simply disable the split horizon mechanism as shown in choice E.Reference: http://www.cisco.com/warp/public/116/fr_faq.htmlQUESTION 695:A new frame-relay network is being implemented and inverse ARP does not appearto be operating correctly. Which alternative command can be used to provideconnectivity?A. frame-relay arpB.
frame-relay mapC. frame-relay interface-dlciD. frame-relay lmi-typeE. frame-relay pvcAnswer: BExplanation: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 addressActualtests.com - The Power of Knowing640-802mapping takes place automatically. Therefore, no static address mapping is required.If the environment does not support LMI autosensing and Inverse ARP, a Frame Relaymap must be manually configured. Use the frame-relay map command to configure staticaddress mapping. Once a static map for a given DLCI is configured, Inverse ARP isdisabled on that DLCI.QUESTION 696:Which of the following Frame-Relay encapsulation commands would you use, if youhad to connect your Cisco router to a non-Cisco router?A. CertK Router(config-if)# Encapsulation frame-relay dot1qB.
CertK Router(config-if)# Encapsulation frame-relay aal5snapC. CertK Router(config-if)# Encapsulation frame-relay ietfD. CertK Router(config-if)# Encapsulation frame-relay islE. None of the aboveAnswer: CExplanation:In general, the IETF Frame Relay encapsulation should be used whenconnecting a Cisco router to non-Cisco equipment across a Frame Relaynetwork.
The IETF Frame Relay encapsulation allows interoperability betweenequipment from multiple vendors.Both Cisco and IETF encapsulations for Frame Relay can be configured on aper-virtual-circuit (VC) basis. This gives greater flexibility whenconfiguring Frame Relay in a multi-vendor environment. A user can specify theFrame Relay encapsulation types to be used on different virtual circuitsconfigured under the same physical interface.Incorrect Answers:A, D: 802.1Q and ISL are trunking encapsulation types and have nothing to do withframe relay.B.
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