Cisco 642-902 Online Practice Questions and Exam Preparation

Cisco 642-902 Online Questions & Answers

• Question 241:

  Refer to the exhibit. ROUTE.com is planning to implement a secure OSPF network to support traffic between clients on the 172.16.10.0/24 network and the file server on the 172.16.20./24 network. You have been asked to review the implementation and verification plans. Which statement about the plan is true?

  

  A. It is complete as written.
  B. It should include a task that verifies that the interarea routes are using the proper MED.
  C. The plan should include a task that verifies that load sharing is active on the appropriate links.
  D. The plan should include a task that verifies end-to-end connectivity between the clients and the file server.
  D. The plan should include a task that verifies end-to-end connectivity between the clients and the file server.

  ---

  The plan for secure OSPF network to support traffic between network and file server requires a task that verifies end-to-end connectivity between the clients and the file server.

• Question 242:

  What are three IPv6 transition mechanisms? (Choose three)

  A. 6to4 tunneling
  B. VPN tunneling
  C. GRE tunneling
  D. ISATAP tunneling
  E. PPP tunneling
  F. Teredo tunneling
  A. 6to4 tunneling
  D. ISATAP tunneling
  F. Teredo tunneling

  ---

  Below is a summary of IPv6 transition technologies:

  6 to 4 tunneling: This mechanism allows IPv6 sites to communicate with each other over the IPv4 network without explicit tunnel setup. The main advantage of this technology is that it requires no end-node reconfiguration and minimal router

  configuration but it is not intended as a permanent solution.

  ISATAP tunneling (Intra-Site Automatic Tunnel Addressing Protocol): is a mechanism for transmitting IPv6 packets over IPv4 network. The word "automatic" means that once an ISATAP server/router has been set up, only the clients must be

  configured to connect to it. Teredo tunneling: This mechanism tunnels IPv6 datagrams within IPv4 UDP datagrams, allowing private IPv4 address and IPv4 NAT traversal to be used. In fact, GRE tunneling is also a IPv6 transition mechanism

  but is not mentioned in BSCI so we shouldn't choose it (there are 4 types of IPv6 transition mechanisms mentioned in BSCI; they are manual, 6-to-4, Teredo and ISATAP).

• Question 243:

  Study this exhibit below carefully.

  

  What is the effect of the distribute-list command in the R1 configuration?

  A. R1 will permit only the 10.0.0.0/24 route in the R2 RIP updates
  B. R1 will not filter any routes because there is no exact prefix match
  C. R1 will filter the 10.1.0.0/24 and the 172.24.1.0/24 routes from the R2 RIP updates
  D. R1 will filter only the 172.24.1.0/24 route from the R2 RIP updates
  C. R1 will filter the 10.1.0.0/24 and the 172.24.1.0/24 routes from the R2 RIP updates

  ---

  The command "distribute-list 10 in Serial0 will create an incoming distribute list for interface serial 0 and refers to access list 10. So it will permit routing updates from 10.0.x.x network while other entries (in this case the 10.1.0.0/24 and 172.24.1.0/24 networks) will be filtered out from the routing update received on interface S0.

• Question 244:

  Given the following partial configuration for Router A: interface serial 0 ip address 10.1.1.1 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint router ospf 7 network 10.1.1.0 0.0.0.255 area 0

  Which two statements are correct? (Choose two.)

  A. DR/BDR elections do not take place.
  B. The area 0 NBMA cloud is configured as more than one subnet.
  C. The router is restricted to a hub and spoke topology.
  D. OSPF neighbor statements are not necessary.
  A. DR/BDR elections do not take place.
  D. OSPF neighbor statements are not necessary.

  ---

  In an OSPF Point-to-Multipoint environment, DB/BDR elections do not take place. The neighbor command became somewhat obsolete with the introduction of the capability to configure other network modes for the interface, regardless of the

  underlying physical topology. Reference: Building Scalable Cisco Networks (Cisco Press) page 130 and 181 Point-to-Multipoint Network:

  Point-to-multipoint is a single interface that connects to multiple destinations. The underlying network treats the network as a series of point-to-point circuits. It replicates LSA packets for each circuit. OSPF traffic is sent as multicast. There is

  no DR or BDR election. This technology uses one IP subnet for all endpoints on the network.

  By default, the network is considered to be a series of point-to-point interfaces. There is no need to specify neighbors, because the neighbors will see each other and simply become adjacent, with no need for the election of a DR or a BDR.

  Point-to-multipoint does not try to reduce adjacencies using a DR. Instead, it accepts the extra overhead of having a full set of adjacencies for the sake of stability. Point-to-multipoint forms an adjacency automatically along any PVC, which

  causes more overhead but is more resilient than NBMA.

• Question 245:

  Refer to the exhibit.

  

  A Boston company bought the assets of a New York company and is trying to route traffic between the two data networks using EIGRP. The show command output shows that traffic will not flow between the networks. As a network consultant, you were asked to modify the configuration and certify the interoperability of the two networks. For traffic to flow from subnet 172.16.8.0/24 to the 172.16.16.0/24 subnet.

  Which configuration change do you recommend?

  A. Turn off autosummarization on routers N1 and B1.
  B. Add IP summary addresses to the Internet-pointing interfaces of routers N1 and B1.
  C. Turn off auto summarization on routers N2 and B2.
  D. Add wildcard masks to the network commands on routers N2 and B2.
  A. Turn off autosummarization on routers N1 and B1.

  ---

  Basically auto route summarization happens at the classful network boundary...so that would make N1 and B1 the locations that summarization would occur for the 172.16.0.0/16 classful networks.

  So if you left auto-summarization enabled on those 2 routers, you would have an issue with discontiguous networks being advertised by both routers N1 and B1 with their classful mask (172.16.0.0/16 and 10.0.0.0/8), which will cause you issues.

  Turning off auto-summarization on N2 and B2 wouldn't make any difference, as their networks wouldn't be summarized due to the fact that they are not meeting a classful boundary on their perspective routers. N1 will receive the 172.16.8.0/24 network from N2 with auto-summarization enabled.

• Question 246:

  An administrator types in the command router ospf 1 and receives the error message:

  "OSPF process 1 cannot start." (Output is omitted.) What should be done to correctly set up OSPF?

  A. Ensure that an interface has been configured with an IP address.
  B. Ensure that an interface has been configured with an IP address and is up.
  C. Ensure that IP classless is enabled.
  D. Ensure that the interfaces can ping their directly connected neighbors.
  B. Ensure that an interface has been configured with an IP address and is up.

  ---

  A loopback interface can override the OSPF router ID. If a loopback interface exists, the router ID is the highest IP address on any active loopback interface. The OSPF router-id command can be used to override the OSPF router ID. Using a loopback interface or a router-id command is recommended for stability.

• Question 247:

  Drag and drop question. Drag each item to its proper location.

  Place the BGP attributes in the correct order used for determining a route.

  Select and Place:

  

  

• Question 248:

  Your Company trainee asks you, in the context of IPv6 and OSPF, what best describes a type 9 LSA? What should you tell her?

  A. Link LSA
  B. Interarea prefix LSA for ABRs
  C. Router LSA
  D. Switch LSA
  E. Intra-area prefix LSA
  F. None of the above
  E. Intra-area prefix LSA

  ---

  Reference: http://packetpushers.net/a-look-at-the-new-lsa-types-in-ospfv3-with-vyatta-and- cisco/ (See LSA Type 9)

• Question 249:

  Refer to the exhibit.

  

  When you examine the routing tables of R1 and R4, you are not able to see the R1 Ethernet subnet on the R4 routing table. You are also not able to see the R4 Ethernet subnet on the R1 routing table.

  Which two configuration changes should be made to resolve this issue? Select the routers where the configuration change will be required, and select the required EIGRP configuration command(s). Choose two answers. (Choose two.)

  A. R1 and R4
  B. R2 and R3
  C. ip summary-address eigrp 1 10.1.1.0 255.255.255.0 and ip summary-address eigrp 1 10.2.2.0 255.255.255.0
  D. variance 2
  E. eigrp stub connected
  F. no auto-summary
  B. R2 and R3
  F. no auto-summary

  ---

  Of course, the routing is going through R2 and R3 to reach R4. So the two routers that need configuration change are R2 and R3. Also you need to set auto-summary to No. The no auto-summary command configures classless routing protocols such as RIPv2 and EIGRP to really act as classless because by default they're classfull.

• Question 250:

  Which IPv6 address correctly compresses the IPv6 unicast address 2001:0:0:0:0DB8:0:0:417A?

  A. 2001:0DB8:417A
  B. 2001::0DB8::417A
  C. 2001:::0DB8::417A
  D. 2001:0DB8:0:0:417A
  E. 2001::DB8:0:0:417A
  F. 2001:::0DB8:0:0:417A
  E. 2001::DB8:0:0:417A

  ---

  The point of this question is the about the different form of Ipv6 address. The IPv6 address is 128 bits long, written as eight 16-bit pieces, separated by colons. Each piece is represented by four hexadecimal digits. You can compact multiple contiguous fields of zero even further. This is the exception to the rule that at least one digit must be present in every field. You can replace multiple fields of zeros with double colons (::). Note that :: can replace only one set of contiguous zero fields. Multiple ::s would make the address ambiguous.