Exam Prep Questions

Question 1	Which of the following are basic functions of a router? (Choose the two best answers.) A. Packet switching B. Packet filtering C. Path determination D. Rapid convergence
A1:	The correct answers are A and C. Routers packet switch when they have determined the best path. Path determination is the process of choosing the best network path from all available network paths. Packet filtering is a technique used to control inbound and/or outbound packets to or from a router. Therefore, answer B is incorrect. Rapid convergence is a design goal of some routing protocols. Therefore, answer D is incorrect.
Question 2	Network routing information distributed among routers is stored in which of the following? A. Flash memory B. Route table C. Metric table D. NVRAM
A2:	The correct answer is B. Route tables contain information about destination networks and the next hop along the optimal path to get there. Flash memory contains the operating system images used by the router. Therefore, answer A is incorrect. Metric information is contained within a router's route table. Therefore, answer C is incorrect. NVRAM contains the router's active configuration files. Therefore, answer D is incorrect.
Question 3	Which of the following conditions is a problem experienced by distance vector routing protocols? A. Split horizon B. Route poisoning C. Counting to infinity D. Maximum hop count E. Hold-down timers
A3:	The correct answer is C. Counting to infinity can result from the slow convergence inherent in distance vector protocols. Split horizon, route poisoning, maximum hop count, and hold-down timers are techniques/items used to reduce the occurrence and impact of the counting-to-infinity situation. Therefore, answers A, B, D, and E are incorrect.
Question 4	Which of the following routing protocols communicates route information by sending the state of its links to all routers in its domain? A. BGP B. OSPF C. IGRP D. RIP
A4:	Answer B is correct. The question is describing a link state protocol and OSPF is an excellent example. Both RIP and IGRP are distance vector protocols, so answers C and D are incorrect. BGP is an exterior routing protocol optimized for passing routing information between domains. Therefore answer A is correct.
Question 5	Which of the following help to mitigate the shortcomings of link state protocols? (Choose the two best answers.) A. Maximum hop count B. Minimize router resource usage C. Coordinate updates D. Route poisoning
A5:	The correct answers are B and C. Lengthening the update frequency or exchanging router summaries at specific border routers helps to minimize router resource usage. Therefore, answer B is correct. Also, attaching timestamps or sequence numbers on link state packets helps to coordinate update information between routers. Therefore, answer C is correct. A maximum hop count and route poisoning address problems with distance vector protocols. Therefore, answers A and D are incorrect.
Question 6	Which of the following are not problems inherent to link state routing protocols? (Choose two.) A. High router resource usage B. Split horizon C. High network bandwidth consumption D. Hold-down timers E. Unsynchronized updates
A6:	The answer is B and D. Split horizons and hold down timers are techniques used to reduce problems in distance vector protocols. High network bandwidth usage and router resource usage are typical of link state protocols when packets are flooding the network during convergence. Therefore, answers C and A are not correct. If link state updates are not synchronized inaccurate SPF trees and route tables can result. This would make answer E incorrect.
Question 7	A friend of yours is implementing a "Just in Time" inventory policy and linking her company network to the networks of several suppliers. Based on just this information, which of the following protocols would you recommend using? A. EIGRP B. OSPF C. BGP D. IP
A7:	Answer C is correct. The key to this question is your friend's decision to connect autonomous domains. Exterior routing protocols are optimized for this task and the only exterior routing protocol available is answer C, Border Gateway Protocol (BGP). Answers A and B are incorrect because they are interior routing protocols. Answer D is incorrect because IP is a routable protocol, not a routing protocol.
Question 8	A large company network is operating at or near capacity. The administrator is about to change routing protocols from EIGRP to OSPF to gain the additional efficacies of a hierarchical protocol. Based on just this information, is this a good idea? A. Yes, EIGRP is a flat routing protocol and not optimized for large implementations . B. Yes, a multipath routing protocol would balance loads in a saturated network and better utilize the bandwidth available. C. No, OSPF typically uses more bandwidth and processor power than EIGRP. D. No, a hierarchical routing protocol is not efficient.
A8:	The correct answer is C. OSPF is a link state routing protocol. Link state protocols are notorious for using large amounts of bandwidth and processor power when coming to convergence. When a network is running at or near capacity, bandwidth and processor power are usually not available. Therefore, transitioning from a distance vector protocol like EIGRP, which uses bandwidth and processing power efficiently , to a link state protocol like OSPF would not be advisable in this situation. Answers A, B, and D are incorrect for the same reason.
Question 9	Why is IP one of the most popular routing protocols available? A. IP provides a flexible addressing structure that is highly scalable. B. IP is the routing protocol of the Internet. As such, its use reduces compatibility issues faced by other routing protocols. C. IP uses a four-layer process which is more efficient than the OSI's seven-layer process. D. None of the above.
A9:	Answer D is correct. IP is not a routing protocol. It is a routable protocol. Therefore, A, B, and C are incorrect and answer D is the only acceptable option.