ActualTests.Cisco.640-802.Exam.Q.and.A.08.15.08-DDU (1130589), страница 54
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Which three of the interfaces shown in the exhibit willparticipate in OSPF according to this configuration statement? (Choose three.)A. Serial0/1.103B. FastEthernet 0/1C. Serail0/1.102D. Serial0/0E. FastEthernet 0/0Answer: B, C, DExplanation:OSPF uses the concept of wildcard masks much like access list filters. OSPF networkmatches are done using the network number and wildcard bits. The network number isthe network portion of the IP address, with the host bits all set to zero. The wildcard bitsdetermine which portion of the address the access list will act on.
Only bits set to zero areacted upon (bits set to one are ignored.) This is the exact opposite of a netmask.Remember that this number is in bits, and you will always have all zeros to the left of thefirst one, and all ones to the right of the last zero. The table below shows some examplesof netmasks and wildcard bits.Actualtests.com - The Power of Knowing640-802In this example, the 192.168.12.64 0.0.0.63 will comprise of all interfaces with an IPaddress in the 192.168.12.64-127 range.QUESTION 482:Part of the Certkiller OSPF network is shown below:Configuration exhibit:Actualtests.com - The Power of Knowing640-802You work as a network technician at Certkiller .com.
Study the exhibits carefully.Assume that all router interfaces are operational and correctly configured. Inaddition, assume that OSPF has been correctly configured on Router Certkiller 2.How will the default route configured on Certkiller 1 affect the operation ofCertkiller 2?A. Any Packet destined for a network that is not referenced in the routing table of RouterCertkiller 2 will be directed to Certkiller 1.
Certkiller 1 will then send that packet back toCertkiller 2 and a routing loop will occurB. Any packet destined for a network that is not directly connected to router Certkiller 1will be droppedC. The networks directly connected to router Certkiller 2 will not be able to communicatewith the 172.16.100.0, 172.16.100.128 and 172.16.100.64 subnetworksD. Any packet destined for a network that is not directly connected to Router Certkiller 2will be dropped immediately because of the lack of a gateway on Certkiller 1E. Any packet destined for a network that is not directly connected to router Certkiller 2will be dropped immediatelyF. None of the aboveAnswer: AQUESTION 483:Certkiller 1 is a Backup Designated Router on the Certkiller OSPF network.
Onwhich types of network will OSPF elect a BDR?A. Nonbroadcast and broadcast multi-accessB. Point-To-Multipoint and multi-accessC. Point-To-Point and Point-To-multipointD. Point-To-Point and multi-accessE. NonBroadcast and Broadcast multipointF. None of the aboveAnswer: AExplanation:Actualtests.com - The Power of Knowing640-802DR and BDR are elected on broadcast and nonbroadcast multi-access networks.Reference: Sybex CCNA Study Guide 4th Edition (Page 283)QUESTION 484:The OSPF interface status of two Certkiller devices is shown below:You work as a network technician at Certkiller and are responsible for the OSPFnetwork. You are troubleshooting the OSPF configuration of routers Certkiller 1 andCertkiller 2.
The routers can't establish an adjacency relationship on their commonEthernet link. The graphic shows the output of the "show ip ospf interface eth0"command for routers Certkiller 1 and Certkiller 2. Based on the information in thegraphic, what is the cause of this problem?A.
The priority on Certkiller 1 should bet set higherB. A backup designated router needs to be added to the networkC. The cost on Certkiller 1 should be set higherD. The OSPF area is not configured properlyE. The hello and dead timers are not configured properlyF. The OSPF process ID numbers must matchG. None of the aboveAnswer: EExplanation:As can be seen above, the hello interval for CK1 has been set to 5 seconds, while it is setto 10 for CK2 .
Also, the dead interval on CK1 is set at 20 seconds while on router CK2 itis set to 40 seconds. In order for two routers to establish an OSPF neigh adjacency, thehello and dead timers must match.Actualtests.com - The Power of Knowing640-802QUESTION 485:Which of the following OSPF commands, when used together, will put the network192.168.10.0/24 into OSPF area 0? (Select all valid responses)A. Router(config-router)# network 192.168.10.0 0.0.0.255 0B.
Router(config-router)# network 192.168.10.0 0.0.0.255 area 0C. Router(config-router)# network 192.168.10.0 255.255.255.0 area 0D. Router(config)# router ospf 0E. Router(config)# router ospf 1Answer: B, EExplanation:B. The network command specifies the IP address (192.168.10.0) followed by thewildcard mask (not the subnet mask), and the area that is to be associated with the OSPFaddress range (in this case, area 0). The wildcard mask indicates in binary how much ofthe IP address much be matched with 0s indicating that the bits must match and 1indicating that they may vary.
Thus 0.0.0.255 or00000000.00000000.00000000.11111111 indicates that any bit in the last octet can varywhile all bits in the first 3 octets must match the network address (in other words,192.168.10.xx)E. The router ospf command enables OSPF routing and enters router configuration mode.This command takes a <process-id> argument which identifies the OSPF process.Incorrect Answers:A. This command is correct, except for the fact that the keyword "area" is missing andneeds to be inserted.C.
For OSPF, the inverse mask must be used, not the regular subnet mask.D. OSPF can not use process ID 0, and the goal of this question is to put a specificnetwork in area 0, not the entire routing process.QUESTION 486:Under which circumstance, i.e. network type, would an OSPF router establish aneighbor adjacency, even though the DR/BDR election process was not performed?A. Point-to-pointB. Broadcast multicastC. Nonbroadcast multicastD. Backbone area 0E. Virtual LinkActualtests.com - The Power of Knowing640-802Answer: AExplanation: If there's a point to point connection, there's no need for a designatedrouter or a backup designated router election.
By definition, only two routers existon a point to point connection.Incorrect Answers:B, C. In these network types, the potential for more than two routers on the segmentexist, so the Designated Router and Backup Designated Routers are elected.D. This is not a network type. Area 0 is the backbone of any OSPF network.E. Virtual Links are used in OSPF to link an area to area 0. Every area must be directlyconnected to area 0 at some point, and virtual links are used for areas that do not meetthis requirement.QUESTION 487:On the assumption that every OSPF router in a particular area is configured withthe same priority value; which secondary value would be used as a router ID whenthere is no loopback interface set?A.
The IP address of the first Fast Ethernet interface.B. The IP address of the console management interface.C. The highest IP address among its active interfaces.D. The lowest IP address among its active interfaces.E. There will be no router ID until a loopback interface is configured.Answer: CExplanation: Ordinarily the loopback interface would be selected as the router ID.In the event that no loopback interface is configured, the router ID will be the firstactive interface that comes up on the router. If that particular interface has morethen one IP address, then the highest address will be selected as the Router ID.Incorrect Answers:B.
Putting an IP address on the management console is a concept that is configured on aCatalyst switch, not a router.QUESTION 488:On the topic of OSPF routing; which of the following are the traits of an OSPFarea? (Select all that apply)A. Each OSPF area requires a loopback interface to be configured.B. Areas may be assigned any number from 0 to 65535.C. Area 0 is called the backbone area.D. Hierarchical OSPF networks do not require multiple areas.Actualtests.com - The Power of Knowing640-802E. Multiple OSPF areas must connect to area 0.F.
Single area OSPF networks must be configured in area 1.G. None of the aboveAnswer: C, EExplanation:OPSF uses areas in a hierarchical fashion, and the backbone area is always area 0. Allother areas have at least one connection to area 0.Incorrect Answers:A. Loopback interfaces are often used in OSPF networks, so that the router ID can beconfigured. However, this is not a requirement.B. The area-id can be an integer between 0 and 4294967295.F.
Single area OSPF networks do not have to be configured with the backbone area 0.Although area 1 can indeed be used, it is not required that area 1 is used. Single areaOSPF networks can be any integer from 0-4294967295.QUESTION 489:If the bandwidth of an OSPF interface on a Certkiller router is configured with the"bandwidth 64" command, what would be the calculated cost of the link?A. 1B. 64C. 1562D. 64000E. 1500F. None of the aboveAnswer: CExplanation: The question states that OSPF interface has been configured with thebandwidth 64command. Cisco IOS always interprets the values for the bandwidthcommand as being in kbps, so the bandwidth is configured as 64 kbps. The metricfor any OSPF defaults to 100,000,000/bandwidth.
So, in this example:100,000,000 / 64000 = 1562.5Reference: Sybex CCNA Study Guide edition 4, page 284.QUESTION 490:Certkiller is using OSPF as the routing protocol in their network. What are some ofthe characteristics of this routing protocol? (Select all valid answer choices)Actualtests.com - The Power of Knowing640-802A. It confines network instability to a single area of network.B. It increases the routing overhead of the networkC. It supports VLSMD. It routes between Autonomous Systems.E.
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