Cisco 642-902 Online Practice Questions and Exam Preparation

Cisco 642-902 Online Questions & Answers

• Question 161:

  Examine the exhibit carefully.

  

  EIGRP is configured on all routers in the network. What conclusion can be derived from the show ip eigrp topology output provided?

  A. Router R1 is waiting for a reply from the neighbor 10.1.2.1 to the hello message sent out inquiring for a second successor to network 10.6.1.0/24.
  B. Router R1 can send traffic destined for network 10.6.1.0/24 out of interface FastEthernet0/0.
  C. Router R1 is waiting for a reply from the neighbor 10.1.2.1 to the hello message sent out before it declares the neighbor unreachable.
  D. Router R1 is waiting for a reply from the neighbor 10.1.2.1 in response to the query sent out about network 10.6.1.0/24.
  D. Router R1 is waiting for a reply from the neighbor 10.1.2.1 in response to the query sent out about network 10.6.1.0/24.

  ---

  The "show ip eigrp topology" command lists all routes that EIGRP is aware of and shows whether EIGRP is actively processing information on that route. Under most normal conditions, the routes should all be in a passive state and no EIGRP

  process are running for that route. If the routes are active, this could indicate the dreaded stuck in active, or SIA, state.

  The fields to note in this output are as follows:

  P-- Passive; no EIGRP computation is being performed. This is the ideal state. A-- Active; EIGRP computations are "actively" being performed for this destination. Routes constantly appearing in an active state indicate a neighbor or query

  problem.

  Both are symptoms of the SIA problem.

  U-- Update; an update packet was sent to this destination. Q-- Query; a query packet was sent to this destination. R-- Reply; a reply packet was sent to this destination. Route information-- IP address of the route or network, its subnet mask,

  and the successor, or next hop to that network, or the feasible successor.

• Question 162:

  Which of the following NSAP addresses is a private, locally administered address?

  A. 39.0f01.0002.0000.0c00.1111.00
  B. 48.0f01.0002.0000.0c00.1111.00
  C. 49.0004.30ac.0000.3090.c7df.00
  D. 52.0f01.0002.0000.0c00.1111.00
  C. 49.0004.30ac.0000.3090.c7df.00

  ---

  Reference: https://sites.google.com/site/amitsciscozone/home/is-is/nsap-addresses

• Question 163:

  Refer to the exhibit.

  

  EIGRP had converged in AS 1 when the link between router R1 and R2 went down. The console on router R2 generated the following messages:

  *Mar 20 12:12:06: %DUAL-5-NBRCHANGE. IP-EIGRP 1: Neighbor 10.1.4.3 (Serial0) is down: stuck in active *Mar 20 12:15:23: %DUAL-3-SIA. Route 10.1.1.0/24 stuck-in-active state in IP-EIGRP 1. Cleaning up The network administrator

  issued the show ip eigrp topology active command on R2 to check the status of the EIGRP network. Which statement best describes the reason for the error messages?

  A. Incorrect bandwidth configuration on router R3 prevents R2 from establishing neighbor adjacency.
  B. Incorrect bandwidth configuration on router R5 prevents R2 from establishing neighbor adjacency.
  C. Router R3 did not reply to the query about network 10.1.1.0/24 sent by router R2 .
  D. Router R5 did not reply to the query about network 10.1.1.0/24 sent by router R2 .
  C. Router R3 did not reply to the query about network 10.1.1.0/24 sent by router R2 .

  ---

  When the link between R1 and R2 is down, R2 loses its successor for the network 10.1.1.0/24. R2 checks its topology table for a feasible successor but it can't find one. So R2 goes active on the that route to find a new successor by sending queries out to its neighbors (R3 and R5) requesting a path to the lost route. Both R3 and R5 also go "active" for the that route. But R5 doesn't have any neighbor to ask besides R2 so it will send an "unreachable message" to indicate it has no alternative path for that route and has no other neighbor to query. R3 also checks its EIRGP topology table for a feasible successor but it has none, too. Unlike R5, R3 has a neighbor (R4) so it continues to query this router. Now suppose there is a problem on the link between R3 and R4 so R4 never receives the query from R3 and of course, R3 also never receives a reply back from R4. Therefore, R3 can't reply back to R2. After about 3 minutes, the "Stuck in active" (SIA) timer on R2 expires and R2 marks the route 10.1.1.0/24 as "stuck in active" route.

  The output line "via 10.1.3.3 (Infinity/Infinity), r, Seiral0, serno 1232 indicates R2 has sent a query to 10.1.3.3 and is waiting for a reply (the lowercase r).

  (Reference: http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008010f016.shtml)

• Question 164:

  Refer to the exhibit.

  

  What happens when the router stops receiving advertisements for the 10.1.2.0/24 network?

  A. The summary route will be removed from the table.
  B. The summary route will remain in the table.
  C. The more specific routes will be advertised from the table.
  D. 10.1.2.0/24 will still be advertised but packets destined for it will be dropped when they reach this router.
  B. The summary route will remain in the table.

  ---

  If you look very closely at the routing table output, we can conclude that R1 has "auto- summary" enabled under the EIGRP routing process.

  D 10.0.0.0/8 is a summary, 00:23:20, Null 0 Anytime the "auto-summary" is enabled under the routing process the router will install a summary route to "null 0" as long as the router has one or more subnets within the "classful" network. In the case above, you have two directly connected interfaces (Serial1 and Serial2) that are within the "classful" network. Therefore, regardless of whether you leran a route via EIGRP that is in the "classful" network, R1 will still install this summary route to "null 0".

• Question 165:

  Study the exhibit below carefully.

  

  In order to summarize all routes from area 0 to area 1, what must be configured on the router?

  A. area 0 range 172.16.96.0 255.255.224.0
  B. area 1 range 172.16.96.0 255.255.224.0
  C. area 1 range 172.16.96.0 255.255.0.0
  D. area 0 range 172.16.96.0 255.255.255.0
  A. area 0 range 172.16.96.0 255.255.224.0

  ---

  This identifies area 0 as the area containing the range of networks to be summarized. The networks will be summarized into area 1. The ABR R1 summarizes the range of subnets from 172.16.32.0 to 172.16.63.0 into one range: 172.16.32.0

  255.255.224.0.

• Question 166:

  Refer to the Exhibit.

  

  Routers in the Diagram are configured with EIGRP. If RTB and RTC fail, which action will RTA take with respect to the HQ network?

  A. RTA will automatically route packets via RTD to the HQ network.
  B. RTA will place the route via RTD into the hold down state.
  C. RTA will go into the active state for all routers.
  D. RTA will go into the active state for the route to HQ network.
  D. RTA will go into the active state for the route to HQ network.

  ---

  When RTB and RTC fails, RTA will go into active state for the HQ network route.

• Question 167:

  Refer to the exhibits. Router B should advertise the network connected to the E0/0/0 interface to router A and block all other network advertisements. The IP routing table on router A indicates that it is not receiving this prefix from router B. What is the probable cause of the problem?

  

  A. An access list on router B is causing the 192.168.3.16/28 network to be denied.
  B. An access list on router B is causing the 192.168.3.32/28 network to be denied.
  C. The distribute list on router B is referencing a numbered access list that does not exist on router B.
  D. The distribute list on router B is referencing the wrong interface.
  A. An access list on router B is causing the 192.168.3.16/28 network to be denied.

  ---

  This is an unclear question. The question says "Router B should advertise the network connected to the E0/0/0 interface to router A and block all other network advertisements. The IP routing table on router A indicates that it is not receiving this prefix from router B." That means the network 192.168.3.16/28 (including the IP 192.168.3.21/28) is not received on router A -> A is the most suitable answer.

  Note: Distribute list are used to filter routing updates and they are based on access lists.

• Question 168:

  EIGRP has been configured to operate over Frame Relay multipoint connections. What should the bandwidth command be set to?

  A. the CIR rate of the lowest speed connection multiplied by the number of circuits
  B. the CIR rate of the lowest speed connection
  C. the CIR rate of the highest speed connection
  D. the sum of all the CIRs divided by the number of connections
  A. the CIR rate of the lowest speed connection multiplied by the number of circuits

  ---

  If the multipoint network has different speeds allocated to the VCs, take the lowest CIR and simply multiply it by the number of circuits. This is because in Frame-relay all neighbors share the bandwidth equally, regardless of the actual CIR of each individual PVC, so we have to get the lowest speed CIR rate and multiply it by the number of circuits. This result will be applied on the main interface (or multipoint connection interface).

• Question 169:

  What is the sequence, from first to last, that OSPF will follow when choosing a router ID?

  A. 1. the highest IP address on any active loopback interface; 2. The router-id command results; 3. The highest IP address of any active physical interface.
  B. 1. the highest IP address on any active loopback interface; 2. The highest IP address of any active Physical interface; 3. The router-id command result.
  C. 1. The highest IP address of any active Physical interface; 2. the highest IP address on any active loopback interface; 3. The router-id command results.
  D. 1. The highest IP address of any active Physical interface; 2. The router-id command result; 3. The highest IP address of any active physical interface.
  E. 1. The router-id command results; 2. The highest IP address of any active Physical interface; 3. The highest IP address of any active physical interface.
  F. 1. the router-id command result; 2. the highest IP address on any active loopback interface; 3. the highest IP address of any active physical interface
  F. 1. the router-id command result; 2. the highest IP address on any active loopback interface; 3. the highest IP address of any active physical interface

  ---

  1.

  The router chooses the numerically highest IP address on any of its loopback interfaces.

  2.

  If no loopback interfaces are configured with IP addresses, the router chooses the numerically highest IP address on any of its physical interfaces. The interface from which the Router ID is taken does not have to be running OSPF.

  Using addresses associated with loopback interfaces has two advantages:

  The loopback interface is more stable than any physical interface. It is active when the router boots up, and it only fails if the entire router fails. The network administrator has more leeway in assigning predictable or recognizable addresses as

  the Router IDs.

  Cisco's OSPF will continue to use a Router ID learned from a physical interface even if the interface subsequently fails or is deleted. Therefore, the stability of a loopback interface is only a minor advantage. The primary benefit is the ability to

  control the Router ID. The OSPF router begins a neighbor relationship by advertising its Router ID in Hello packets.

• Question 170:

  Refer to the exhibit.

  

  AS 65500 is running OSPF as its IGP and has two eBGP connections to the Internet provider AS 65501. The provider requires that you advertise all of the prefixes in AS 65500 to the provider as a single 192.168.12.0/22 route. Currently only Routers A and B are able to reach the Internet. Which of the following additions to the configuration will solve this issue?

  A. RouterA(config)#ip cef
  B. RouterA(config)# ip route 192.168.12.0 255.255.252.0 null 0
  C. RouterA(config-router)#ebgp multihop 1
  D. RouterA(config-router)#redistribute ospf 1
  E. RouterA(config-router)#neighbor 192.168.14.253 next-hop-self
  F. RouterA(config-router)#neighbor 192.168.14.253 local-as 65500
  B. RouterA(config)# ip route 192.168.12.0 255.255.252.0 null 0

  ---

  The synchronization rule states "A BGP router should not use, or advertise to an external neighbor, a route learned by IBGP, unless that route is local or is learned from the IGP".

  Notice that IGP here can be a static route.

  In this case, unless there is an entry about network 192.168.12.0 in the routing table of RouterA, RouterA will not advertise this network to its EBGP -> B is correct (even if this static route points to Null0).

  Note: Although this question states that OSPF is being used as IGP but for some reasons, network 192.168.12.0/22 is not advertised to RouterA -> RouterA does not have this route in its routing table.