Cisco 642-902 Online Practice Questions and Exam Preparation

Cisco 642-902 Online Questions & Answers

• Question 261:

  Refer to the exhibit.

  

  A. Interface authentication must be configured.
  B. The routing processes must be configured with an area ID.
  C. IP unicast routing must be enabled.
  D. IPv4 addresses must be applied to the interfaces.
  C. IP unicast routing must be enabled.

  ---

  Reference:

  http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_55_se/con figuration/guide/swiprout.html

• Question 262:

  An engineer is trying to summarize the following networks using the "ip summary-address eigrp" command:

  10.8.88.0/25 10.8.89.48/29 10.8.64.96/27

  Which network and subnet mask below would be the smallest EIGRP summary address to include all three subnets?

  A. 10.8.64.0 255.255.224.0
  B. 10.8.64.0 255.255.128.0
  C. 10.8.64.0 255.255.192.0
  D. 10.8.0.0 255.255.192.0
  A. 10.8.64.0 255.255.224.0

  ---

  10.8.64.0 255.255.224.0 will include networks 10.8.64.0 - 10.8.96.255, so this would be the smallest summary route that would include the 3 routes listed in the question.

• Question 263:

  Refer to the exhibit.

  A new TAC engineer came to you for advice. A GRE over IPsec tunnel was configured, but the tunnel is not coming up.

  What did the TAC engineer configure incorrectly?

  A. The crypto isakmp configuration is not correct.
  B. The crypto map configuration is not correct.
  C. The interface tunnel configuration is not correct.
  D. The network configuration is not correct; network 172.16.1.0 is missing.
  A. The crypto isakmp configuration is not correct.

• Question 264:

  Refer to the exhibit. All routers have simultaneously been reloaded, and the DR election has concluded as expected. Which state is RTC in?

  

  A. 2WAY/DROTHER
  B. 2WAY/BDR
  C. 2WAY/DR
  D. FULL/DROTHER
  E. FULL/BDR
  F. FULL/DR
  E. FULL/BDR

  ---

  http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094059.shtml All the routers are allowed to take part in the DR/BDR election because all the "Pri"s (Priority) are 1 and they are equal so with default parameters, the router with highest IP address will become DR (RTD in this case) and the router with second highest IP address (RTC) will become BDR.

• Question 265:

  What are the four main steps in configuring a GRE tunnel over IPsec on Cisco routers? (Choose Four)

  A. Configure a physical interface or create a loopback interface to use as the tunnel endpoint.
  B. Create the GRE tunnel interfaces.
  C. Add the tunnel interfaces to the routing process so that it exchanages routing updates across that interface.
  D. Add the tunnel subnet to the routing process so that it exchanages routing updates across that interface.
  E. Add all subnets to the crypto access-list, so that IPsec encrypts the GRE tunnel traffic.
  F. Add GRE traffic to the crypto access-list, so that IPsec encrypts the GRE tunnel traffic.
  A. Configure a physical interface or create a loopback interface to use as the tunnel endpoint.
  B. Create the GRE tunnel interfaces.
  D. Add the tunnel subnet to the routing process so that it exchanages routing updates across that interface.
  F. Add GRE traffic to the crypto access-list, so that IPsec encrypts the GRE tunnel traffic.

  ---

  Reference: http://www.cisco.com/public/technotes/smbsa/en/us/internet/Sec_GRE_tunnel_ovr_IPSEC.p df

• Question 266:

  Which two statements are true of the OSPF link-state routing protocol? (Choose two.)

  A. Using the Bellman-Ford algorithm, each OSPF router independently calculates its best paths to all destinations in the network.
  B. Using the DUAL algorithm, each OSPF router independently calculates its best paths to all destinations in the network.
  C. OSPF sends summaries of individual link-state entries every 30 minutes to ensure LSDB synchronization.
  D. OSPF sends triggered updates when a network change occurs.
  E. OSPF sends updates every 10 seconds.
  F. When a link changes state, the router that detected the change creates a link-state advertisement (LSA) and propagates it to all OSPF devices using the 224.0.0.6 multicast address.
  C. OSPF sends summaries of individual link-state entries every 30 minutes to ensure LSDB synchronization.
  D. OSPF sends triggered updates when a network change occurs.

  ---

  The point of this question is the basis of OSPF.

  Incorrect answer A. OSPF send hello packets every 10 seconds, not the updates, OSPF sends triggered updates when a network change occurs. For OSPF, D Rother use the multicast address 224.0.0.6 to send packets to DR and BDR, only

  DR and BDR can get the information from this multicast address.

• Question 267:

  Which statement about a non-zero value for the load metric (k2) for EIGRP is true?

  A. A change in the load on an interface will cause EIGRP to recalculate the routing metrics and send a corresponding update out to each of its neighbors.
  B. EIGRP calculates interface load as a 5-minute exponentially weighted average that is updated every 5 minutes.
  C. EIGRP considers the load of an interface only when sending an update for some other reason.
  D. A change in the load on an interface will cause EIGRP to recalculate and update the administrative distance for all routes learned on that interface.
  C. EIGRP considers the load of an interface only when sending an update for some other reason.

  ---

  The load metric (k2) represents the worst load on a link between source and destination. EIGRP routing updates are triggered only by a change in network topology (like links, interfaces go up/down, router added/removed), and not by change in interface load or reliability. The load is a five minute exponentially weighted average that is updated every five seconds (not five minutes) .

  EIGRP considers the load of an interface only when sending an update for some other reason (like a link failure)

• Question 268:

  

  The company and the company network have both been growing rapidly. Multiple adds, moves and changes have been applied to the network. Your boss has asked you to troubleshoot a recent OSPF synchronization problem that has

  arisen. There have been synchronization problems at separate locations in the OSPF area 0. There have been reported link failures during the rapid growth of the company network. You are required to resolve the OSPF problem. OSPF must

  be able to converge when the network changes. Refer to the information above to answer the following question.

  The log of d1 reports the following:

  

  This event was anticipated due to maintenance; however, it resulted in excessive lost routes. Which route should be the only one removed from the routing tables of the routers?

  A. 8.187.175.82/32
  B. 10.138.43.0/30
  C. 10.206.180.0/30
  D. 4.249.113.59/32
  E. 10.201.0.0/30
  F. None of the above
  E. 10.201.0.0/30

  ---

  From the log we learn that the link of Interface Fa0/1 has been down. This link belongs to network 10.201.0.0/30 so we just need to remove this route from the routing table.

• Question 269:

  Refer to exhibit.

  

  RouterA (DR) failed, and after 10 minutes it came back. Which two statements are true? (Choose two)

  A. RouterA is a DR
  B. RouterA is a BDR
  C. RouterA is a DROTHER
  D. RouterB is a DR
  E. RouterB is a BDR
  F. RouterC is a DROTHER
  C. RouterA is a DROTHER
  D. RouterB is a DR

  ---

  Reference: http://packetlife.net/blog/2011/jun/2/ospf-designated-router-election/

• Question 270:

  Which two statements are true about IBGP neighbor relationships? (Choose two.)

  A. An EGP or static routing is required between IBGP neighbors.
  B. A full-mesh IBGP requires that neighbor relationships be established between all BGP enabled routers in the autonomous system.
  C. IBGP neighbors must be in different autonomous systems.
  D. The BGP split-horizon rule specifies that routes learned via EBGP are never propagated to other IBGP peers.
  E. The BGP split horizon rule specifies that routes learned via IBGP are never propagated to other IBGP peers.
  B. A full-mesh IBGP requires that neighbor relationships be established between all BGP enabled routers in the autonomous system.
  E. The BGP split horizon rule specifies that routes learned via IBGP are never propagated to other IBGP peers.

  ---

  Reference: http://packetlife.net/wiki/bgp/ (see confederations)