Design IP addressing and routing protocols

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Questions derived from the 640-863 - Designing for Cisco Internetwork Solutions Exam Cisco Self-Test Software Practice Test.

Objective: Design IP addressing and routing protocols
SubObjective: Identify routing protocol considerations in an enterprise network

Item Number: 640-863.5.2.14
Single Answer, Multiple Choice

You are the network consultant for Metroil Corp. The company’s chief technical officer (CTO) wants the routing protocol to be implemented with the following characteristics:

1. Supports multiple large networks.
2. Does not require a hierarchical physical topology.
3. Provides loop prevention and fast convergence.
4. Provides load balancing.
5. Supports variable length subnet mask (VLSM) and classless inter-domain routing (CIDR).

Which of the following protocols meet the requirements of the network?

1. Intermediate System-to-Intermediate System (IS-IS)
2. Open Shortest Path First (OSPF)
3. Routing Information Protocol version 2 (RIPv2)
4. Enhanced Interior Gateway Routing Protocol (EIGRP)

Answer:
D. Enhanced Interior Gateway Routing Protocol (EIGRP)

Tutorial:
Enhanced Interior Gateway Routing Protocol (EIGRP) meets the requirements of the network.

EIGRP is a classless protocol that allows the use of variable length subnet mask (VLSM) and supports classless inter-domain routing (CIDR) for allocation of IP addresses. Following are the characteristics of EIGRP:

• Supports large networks because of high scalability.
• Does not require a hierarchical physical topology.
• Provides loop prevention and fast convergence by using diffusing update algorithm (DUAL).
• Performs equal and unequal load balancing by default.
• Supports VLSM and CIDR.
• Is a hybrid routing protocol (distance-vector protocol that also provide link-state protocol characteristics).
• Is a classless protocol.
• Sends partial route updates only when there are changes.
• Supports Message-Digest algorithm 5 (MD5) authentication.
• Administrative distance is 90 for EIGRP internal routes, 170 for EIGRP external routes and 5 for EIGRP summary routes.
• Is only used with Cisco platforms.

The option Intermediate System-to-Intermediate System (IS-IS) is incorrect because IS-IS requires a hierarchical physical topology and it does not provide loop prevention by default.

The option OSPF is incorrect because OSPF requires a hierarchical physical topology.

The option RIPv2 is incorrect because RIPv2 does not support large multiple networks, requires a hierarchical physical topology and it does not provide loop prevention by default.

Reference:
http://www.ciscopress.com/articles/article.asp?p=102174&seqNum=6&rl=1