QUESTION 11 You are the network administrator at Cisco Highway. You want to minimize the effect of routing table updates on internal routers when a WAN interface changes its state from up to down on a frequent basis. What strategy should you implement?

A. Use private IP addresses.

B. Use dial-on-demand routing.

C. Use a routing protocol that tolerates route flapping.

D. Use route summarization.

E. Use a distance vector routing protocol. Answer: D Explanation: Another advantage to using route summarization in a large complex network is that it can isolate topology changes from other routers. That is, if a specific link in the domain were flapping (going down and up rapidly), the summary route would not change, so no router external to the domain would need to keep modifying its routing table due to this flapping activity. Reference: Building Scalable Cisco Networks (Cisco press) page 76

QUESTION 12 What happens when a BGP route reflector receives update from a peer in another autonomous system?

A. It sends the update only to routers in that autonomous system.

B. It sends the update to all routers in the network.

C. It ignores update from nonclients peers.

D. It sends the update to all BGP peers.

E. It discards the update. Answer: D Explanation: When a BGP route reflector receives update from a peer in another autonomous system, it sends the update to all BGP peers in the network.

Reference: BSCI Self Study Cisco Press (2003) 2nd Edition, page 490.

QUESTION 13 Study the Exhibit below carefully:

On the S0 interface of router Cisco Highway1, what is the default OSPF network type?

A. Nonbroadcast

B. Point-to-point

C. Broadcast

D. Point-to-multipoint

E. Point-to-multipoint nonbroadcast Answer: E Explanation: There are three different scenarios for NBMA interfaces.

• Pure Multipoint Configuration (No Subinterfaces)
• Pure Point-to-Point Configuration (each VC on a separate subinterface)
• Hybrid Configuration (point-to-point and multipoint subinterfaces) Reference: http://www.cisco.com/en/US/tech/tk365/tk207/technologies_tech_note09186a0080094063.shtml#hybrid

QUESTION 14 Match the OSPF area type in the options by dragging-and-dropping it to the description in the target area.

Answer:

Explanation:

• Stub Areas: These areas do not accept routes belonging to external autonomous systems (AS); however, these areas have inter-area and intra-area routes. In order to reach the outside networks, the routers in the stub area use a default route which is injected into the area by the Area Border Router (ABR).
• Normal Areas: These areas can either be standard areas or transit (backbone) areas. Standard areas are defined as areas that can accept intra-area, inter-area and external routes.
• backbone area is the central area to which all other areas in OSPF connect.
• Totally Stub Areas: These areas do not allow routes other than intra-area and the default routes to be propagated within the area. The ABR injects a default route into the area and all the routers belonging to this area use the default route to send any traffic outside the area.
• NSSA: This type of area allows the flexibility of importing a few external routes into the area while still trying to retain the stub characteristic. Assume that one of the routers in the stub area is connected to an external AS running a different routing protocol, it now becomes the ASBR, and hence the area can no more be called a stub area. However, if the area is configured as a NSSA, then the ASBR generates a NSSA external link-state advertisement (LSA) (Type-7) which can be flooded throughout the NSSA area. These Type-7 LSAs are converted into Type-5 LSAs at the NSSA ABR and flooded throughout the OSPF domain Reference: http://www.cisco.com/en/US/tech/tk365/tk480/technologies_tech_note09186a0080094a74.shtml

QUESTION 15 What is the IP address which is known as the all OSPF DRs and BDRs address?

A. 224.0.0.9

B. 224.0.0.6

C. 224.0.0.5

D. 224.0.0.11 Answer: B

Explanation: 224.0.06 is the address of all OSPF DRs and BDRs. Reference: Building Scalable Cisco Networks (Cisco press) page 114

QUESTION 16 Study the exhibit of a BGP configuration below carefully. Which BGP network statement will inject the 10.10.0.0/16 prefix in the BGP table? interface ethernet 0 ip address 10.10.10.1 255.255.0.0 ! int serial 0 ip address 172.16.1.1 255.255.255.252 ! router bgp 65001 neighbor 192.168.1.1 remote-as 65002

A. network 10.10.10.1 mask 255.255.255.255

B. network 10.10.0.0 mask 255.255.0.0

C. network 10.0.0.0 mask 255.255.0.0

D. network 10.0.0.0

E. network 10.10.10.0 mask 255.255.255.0 Answer: B

QUESTION 17 Of the following which are the characteristics of an Autonomous System (AS) in a BGP network? (Choose all that apply.)

A. Within an AS, routers learned through an interior protocol cannot be redistributed using BGP to other autonomous systems.

B. An AS is a group of routers under the same technical administration.

C. An AS uses exterior gateway protocols (EGPs) to exchange information with other autonomous systems.

D. Within an AS, routes learned through BGP can be redistributed using interior gateway protocols.

E. Within an AS, all routers must run either BGP or IBGP. Answer: B C D Explanation:

• Exterior Gateway Protocol (EGP) routing protocol used to connect between autonomous systems.
• The use of the term autonomous system in connection with BGP stresses the fact that the administration of an autonomous system appears to other autonomous systems to have a single coherent interior routing plan, and presents a consistent picture of those networks that are reachable through it.
• BGP is used between autonomous systems Reference: Building Scalable Cisco Networks (Cisco press) page 313

QUESTION 18 Where can route summarization be done, when one uses VLSM in an EIGRP network?

A. Manually on any router interface.

B. Dynamically at the supernet boundary.

C. Only at classful network boundaries.

D. Only at classless network boundaries. Answer: A Explanation: EIGRP allows you to summarize internal and external routes on virtually any bit boundary using manual summarization Source: CCNP Self-Study CCNP BSCI Exam Certification Guide Third Edition P.482 Topic: Summarization with EIGRP Proof: Summarization in EIGRP solves the same scaling issues seen in other networks. The difference in the configuration between EIGRP and OSPF is that OSPF is summarized only at the area boundary. Because EIGRP does not use the concept of areas, summarization can be configured on any router interface in the network. Consideration of where to summarize is determined by the hierarchical structure of the network. If summarization is not configured, EIGRP will automatically summarize at the class boundary.

QUESTION 19 You are a technician at Cisco Highway. Your newly appointed Cisco Highway trainee wants to know under which circumstances you would use static routing in stead of a dynamic routing protocol. What would your reply be? (Choose all that apply.)

A. High degree of control in path selection is required.

B. Low maintenance routing is required.

C. Networks with a single entry point.

D. Highly adaptable networks.

E. A medium to large network with redundant paths. Answer: A, C Explanation:

• Define specific routs to use when two autonomous systems must exchange routing information, rather than having entire routing tables exchanged.
• Define routes to destinations over a WAN link to eliminate the need for a dynamic routing protocol- that is, when you do not want routing updates to enable or cross the link.

C: Networks with a single entry point have no real benefit, and would be a waste of router resources. A default route is usually used in this case. Reference: Building Scalable Cisco Networks (Cisco press) page 463 Not E: Medium to large networks benefit from dynamic routing.

QUESTION 20 You are the network administrator at Cisco Highway. One of the Cisco Highway trainees wants to know how to perform route redistribution when exchanging routes between two protocols. What would your reply be? (Choose all that apply.)

A. Use static routes when there is only one path.

B. Use one way route distribution when there are multiple paths.

C. Use static routes when there are multiple paths.

D. Use two way route redistribution where there are multiple paths.

E. Use one way route redistribution when there is only one path.

F. Use two way route distribution when there is only one path. Answer: B C Explanation:

B. One way redistribution- To avoid routing loops and problems with varying convergence time, allow routes to be exchanged in only one direction, not both directions. In the other direction, you should consider a default route.

C. When you want to prevent routing loops - Many companies have large enough networks that redundant paths are prominent. In some cases, for example, when a path to the same destination is learned from two different routing protocols, you may want to filter the propagation of one of the paths. Reference: Building Scalable Cisco Networks (Cisco press) page 472