Cisco 642-902 Online Practice Questions and Exam Preparation

Cisco 642-902 Online Questions & Answers

• Question 151:

  Refer to the exhibit. EIGRP has been configured on routers R1 and R2. However, R1 does not show R2 as a neighbor and does not accept routing updates from R2. What could be the cause of the problem?

  

  A. The no auto-summary command has not been issued under the EIGRP process on both routers.
  B. Interface E0 on router R1 has not been configured with a secondary IP address of 10.1.2.1/24.
  C. EIGRP cannot exchange routing updates with a neighbor's router interface that is configured with two IP addresses.
  D. EIGRP cannot form neighbor relationship and exchange routing updates with a secondary address.
  D. EIGRP cannot form neighbor relationship and exchange routing updates with a secondary address.

  ---

  EIGRP updates always use the primary IP address of the outgoing interface as the source address. In this case R2 will use the 10.1.2.2/24 address, which is not in the same subnet of R1, to send EIGRP update to R1. Therefore R1 does not accept this update and generates the "not on common subnet" error message.

  Answer D is a bit unclear. It should state that "EIGRP cannot form neighbor relationship and exchange routing updates if the two primary addresses on two routers are not in the same subnet".

  Notice that although R1 does not accept R2 as its EIGRP neighbors but R2 accepts R1 as its EIGRP neighbor accepts R1 hello packets.. For more information about this problem, please read http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a008009 3f09.shtml.

• Question 152:

  Refer to the exhibit.

  

  What is the effect of the OSPF configuration on router B?

  A. All interfaces will be in area 0.
  B. The router will be an ABR with s1/0 in area 0 and f0/0 and 0/1 in area 1.
  C. The router will be an ABR with s1/0 in area 0 and f0/0 and 0/1 in area 2.
  D. The router will be an ABR with s1/0 in area 0, f0/0 in area 1, and f0/1 in area 2.
  D. The router will be an ABR with s1/0 in area 0, f0/0 in area 1, and f0/1 in area 2.

  ---

  Reference: https://www.google.com/url? sa=tandrct=jandq=andesrc=sandsource=webandcd=4andcad=rjaandved=0CEIQFjADandurl=https%3A %2F%2Flearningnetwork.cisco.com%2Fservlet%2FJiveServlet% 2Fdownload%2F4907- 2332%2FCase%2520..andei=sU-rUeGvFIanhAfRIHwDQandusg=AFQjCNH4zqER_WNMrHEY2VhuMzDTy7D1xQandsig2=v1xlJWspSrBE6sz oQAP8cgandbvm=bv.47244034,d.ZG4

• Question 153:

  What is the difference between the IPv6 addresses ::/0 and ::/128?

  A. ::/0 is the default route, and ::/128 is the unspecified address.
  B. ::/0 is the unicast address, and ::/128 is the anycast address.
  C. ::/0 is the anycast address, and ::/128 is the multicast address.
  D. ::/0 is the unicast address, and ::/128 is the multicast address.
  E. ::/0 is the unspecified address, and ::/128 is the multicast address.
  F. ::/0 is the anycast address, and ::/128 is the default address.
  A. ::/0 is the default route, and ::/128 is the unspecified address.

  ---

  Reference: http://tools.ietf.org/html/rfc5156

• Question 154:

  Which show command will display only the Type 5 LSAs in the OSPF topology database?

  A. show ip ospf database external
  B. show ip ospf database nssa-external
  C. show ip route ospf
  D. show ip ospf database summary
  E. show ip route
  A. show ip ospf database external

  ---

  The "show ip ospf database external" command displays information only about external LSAs (Type 5 LSAs).

  Below is an example of the "show ip ospf database external" command

  Notice the line "LS Type: AS External Link", which means LSA Type 5. For your information, the "Link State ID: 143.105.0.0 indicates the network being advertised; the "Advertising Router: 10.187.70.6 indicates the router that originated this LSA.

  Note:

  + The "show ip ospf database summary" command displays information only about the summary LSAs. + The "show ip ospf database nssa-external" command displays information only about the not so stubby area (NSSA) external LSAs.

  

• Question 155:

  Into which two types of areas would an area border router (ABR) inject a default route? (Choose two.)

  A. stub
  B. the autonomous system of an exterior gateway protocol (EGP)
  C. NSSA
  D. totally stubby
  E. the autonomous system of a different interior gateway protocol (IGP)
  F. area 0
  A. stub
  D. totally stubby

  ---

  Both stub area and totally stubby area allow an ABR to inject a default route. The main difference between these 2 types of areas is:

  + Stub area replaces LSA Type 5 (External LSA created by an ASBR to advertise network from another autonomous system) with a default route + Totally stubby area replaces both LSA Type 5 and LSA Type 3 (Summary LSA created by an ABR to advertise network from other areas, but still within the AS, sometimes called interarea routes) with a default route.

  Below summarizes the LSA Types allowed and not allowed in area types:

  

• Question 156:

  When an EIGRP topology change is detected, what is the correct order of events when there is a FS?

  A. The neighbor adjacency is deleted. The feasible route is used. DUAL is notified. Remove all topology entries learned from that neighbor.
  B. DUAL is notified. Remove all topology entries learned from that neighbor. The neighbor adjacency is deleted. Routes enter the Active state and the feasible route is used.
  C. The neighbor adjacency is deleted. Routes enter the Active state and the feasible route is used. DUAL is notified. Remove all topology entries learned from that neighbor.
  D. DUAL is notified. The neighbor adjacency is deleted. Remove all topology entries learned from that neighbor. The feasible route is used.
  D. DUAL is notified. The neighbor adjacency is deleted. Remove all topology entries learned from that neighbor. The feasible route is used.

  ---

  If a packet is not received before the expiration of the hold time, the neighbor adjacency is deleted, and all topology table entries learned from that neighbor are removed, as if the neighbor had sent an update stating that all the routes are unreachable. If the neighbor is a successor for any destination networks, those networks are removed from the routing table, and alternative paths, if available, are computed. This lets the routes quickly reconverge if an alternative feasible route is available.

• Question 157:

  Refer to the exhibit.

  

  The customer has reported an issue about eBGP loading. Currently the AS 100 eBGP links have an average outbound load of 65% and 20% respectively. On further investigation, traffic from 10.10.24.0 accounts for 45%, and 10.10.25.0 and

  10.10.32.0 accounts for 20% each of the outbound load. The customer wants to spread the load between the two eBGP links more evenly. The BGP attributes are currently set at their default values. If you are located at AS 100 and want to influence how AS 100 sends traffic to AS 200, what BGP attribute would you configure to cause AS 100 outbound traffic to load the eBGP links more evenly?

  A. On router A, set the default local-preference to 50.
  B. On router B, set the default metric to 150.
  C. On router B, configure a route map for 10.10.25.0/24 that sets the local preference to 150.
  D. On router B, set the default local-preference to 150.
  C. On router B, configure a route map for 10.10.25.0/24 that sets the local preference to 150.

  ---

  To make the eBGP links more evenly we should use the link B-F for network 10.10.25.0/24 so that the total traffic going through B-F link is about 40%. In this case we should apply a route map on B to set the local preference of 10.10.25.0/24 to a higher value than 100. But notice that we must use a second clause to permit other traffic if not they will be filtered out.

  Note: The default value for local preference is 100. A path with higher local preference is preferred.

• Question 158:

  What is the IPv6 address FF02::2 used for?

  A. all hosts in a local segment
  B. all routers in a local segment
  C. all hosts in a particular multicast group
  D. all routers in an autonomous system
  B. all routers in a local segment

  ---

  To identify all nodes for the node-local and link-local scopes, the following multicast addresses are defined:

  

  FF01::1 (node-local scope all-nodes address)

  

  FF02::1 (link-local scope all-nodes address)

  To identify all routers for the node-local, link-local, and site-local scopes, the following multicast addresses are defined:

  

  FF01::2 (node-local scope all-routers address)

  

  FF02::2 (link-local scope all-routers address)

  

  FF05::2 (site-local scope all-routers address)

  Reference: http://technet2.microsoft.com/windowsserver/en/library/8c07faf2-35b3-4f2a- 920f-d61ad76581ad1033.mspx?mfr=true

• Question 159:

  Look at the following configuration below and select the statements that are true.

  RD2(config)#router ospf 100 RD2(config-router)# distance 180 10.1.10.1 0.0.0.0 match-me RD2(config-router)#! RD2(config-router)#ip access-list standard match-me RD2(config-std-nacl)# permit host 172.16.0.0 Choose two.

  A. OSPF will have an AD of 180 for routes from 10.1.10.1 in the 172.16.0.0/16 range.
  B. The neighbor RID is 10.1.10.1
  C. OSPF will have an AD of 180 for all routes.
  D. The local RID is 10.1.10.1
  A. OSPF will have an AD of 180 for routes from 10.1.10.1 in the 172.16.0.0/16 range.
  B. The neighbor RID is 10.1.10.1

  ---

  If you see the configuration, the OSPF will be having an AD of 180 routers from 10.1.10.1 in the range permitted by the host. Since the distance 180 is configured the neightbor RID will be 10.1.10.1.

• Question 160:

  Refer to the following.

  Router # sh ip route eigrp 13.0.0.0/8 is variably subnetted, 2 subnets, 2 masks D 13.0.0.0/8 is a summary, 00:00:32, Null0

  What happens to packets that are forwarded from the 13.0.0.0/8 network to the Null0 interface?

  A. Flagged
  B. Accepted
  C. Summarized
  D. Dropped
  D. Dropped

  ---

  When an EIGRP router summarizes, it automatically builds a route to null0 for the summarized route. The router to null0 prevents packets that do not match a specific entry in the routing table from following a default route. (The route to null0 causes the packet to be dropped).