EIGRP Questions

1. Your company is running IGRP using an AS of 10. You want to configure EIGRP on the network but want to migrate slowly to EIGRP and don't want to configure redistribution. What command would allow you to migrate over time to EIGRP without configuring redistribution? A. router eigrp 11 B. router eigrp 10 C. router eigrp 10 redistribute igrp D. router igrp combine eigrp 10

1. B. If you enable EIGRP on a router with the same autonomous system (AS) number, EIGRP will automatically redistribute IGRP into EIGRP. You will see the IGRP injected routes as external (EX) routes with an EIGRP AD of 170. This is a nice feature that lets you migrate slowly to EIGRP with no extra configuration.

1. What four routed protocols are supported by EIGRP?

1. The four routed protocols supported by EIGRP are IP, IPv6, IPX, and AppleTalk.

10. A network administrator needs to configure a router with a distance-vector protocol that allows classless routing. Which of the following satisfies those requirements? A. IGRP B. OSPF C. RIPv1 D. EIGRP E. IS-IS

D. In this question, we're calling EIGRP just plain old distance vector. EIGRP is an "advanced" distance-vector routing protocol, sometimes called a hybrid routing protocol because it uses the characteristics of both distance-vector and link-state routing protocols.

16. EIGRP is an open standard routing protocol. True/False?

16. False, EIGRP is a Cisco proprietary protocol. It is described as either a Hybrid or an "Advanced Distance Vector" protocol

17. Describe several of EIGRP's key features.

17. Will route multiple routed protocols. Extremely fast convergence. No requirement for hierarchical design. Multicast and unicast (no broadcast). Incremental updates, Flexible summarization. Equal and Unequal cost load balancing. Flexible router authentication.

18. In an EIGRP routers topology table, what is the difference between the Feasible Distance and the Advertised Distance?

18. The Feasible Distance represents that routers TOTAL cost to reach the destination network using the respective neighbor. The Advertised Distance is the NEIGHBORs cost to reach the destination network.

19. Describe the "feasibility check" rule.

19. The Feasibility Check in EIGRP says that in order for a neighbor to be considered a "feasible successor" to a destination network that neighbors cost to the network must be LESS THAN the feasible distance of the calculating router.

2. Which EIGRP information is held in RAM and maintained through the use of Hello and update packets? (Choose two.) A. Neighbor table B. STP table C. Topology table D. DUAL table

2. A, C. EIGRP holds three tables in RAM: neighbor, topology, and routing. The neighbor and topology tables are built and maintained with the use of Hello packets.

2. When is redistribution required for EIGRP?

2. Redistribution is required when more than one EIGRP session or process is running and they are identified with different ASNs. Redistribution shares topology information between EIGRP sessions.

20. What are the two default pieces of information used by EIGRP as part of it's metric calculation and what are the two pieces that can be optionally configured?

20. The default metric is calclated using minimum Bandwidth + aggregate Delay. Load and Reliability are optional parameters.

3. What command would be used to enable EIGRP with an autonomous system number of 300?

3. router eigrp 300

4. What command will tell EIGRP that it is connected to network 172.10.0.0?

4. network 172.10.0.0

5. What type of EIGRP interface will neither send nor receive Hello packets?

5. Passive interface

8. What are the multicast addresses for RIP v2, OSPF (all routers and DR's) and EIGRP?

8. 224.0.0.9, 224,0,0,5 and 6, and 224.0.0.10

13. Which is true regarding EIGRP successor routes? (Choose two.) A. A successor route is used by EIGRP to forward traffic to a destination. B. Successor routes are saved in the topology table to be used if the primary route fails. C. Successor routes are flagged as "active" in the routing table. D. A successor route may be backed up by a feasible successor route. E. Successor routes are stored in the neighbor table following the discovery process.

A, D. Successor routes are the routes picked from the topology table as the best route to a remote network, so these are the routes that IP uses in the routing table to forward traffic to a remote destination. The topology table contains any route that is not as good as the successor route and is considered a feasible successor, or backup route. Remember that all routes are in the topology table, even successor routes.

QUESTION NO: 313 Which routing protocol by default uses bandwidth and delay as metrics? A. EIGRP B. RIP C. BGP D. OSPF

Answer: A Explanation: This question tests the metrics of various routing protocols. RIP uses hop-count as metrics; BGP uses complicated path attributes as metrics; OSPF uses bandwidth as metrics; and EIGRP uses bandwidth and delay as metrics by default.

QUESTION NO: 304 A router learns about a remote network from EIGRP, OSPF, and a static route. Assuming all routing protocols are using their default administrative distance, which route will the router use to forward data to the remote network? A. The router will use the static route. B. The router will use the OSPF route. C. The router will load balance and use all three routes. D. The router will use the EIGRP route.

Answer: A Explanation: When a router learns about the same network via multiple sources, the router will choose the source with the lowest administrative distance (AD). By default, the AD for these routing protocols are: Connected Interface has 0 AD Static Route : 1 EIGRP : 90 OSPF : 110 So, the static route will be chosen since it has the lowest AD.

As a cisco technician, you need to know EIGRP protocol very well. Which of the following is true about EIGRP successor routes? (Choose two.) A. A successor route is used by EIGRP to forward traffic to a destination. B. Successor routes are stored in the neighbor table following the discovery process. C. A successor route may be backed up by a feasible successor route. D. Successor routes are flagged as "active" in the routing

Answer: A,C Explanation: The following are some terms relating to EIGRP: 1. Feasible Distance : The lowest calculated metric to each destination 2. Feasibility Condition : A condition that is met if a neighbor's advertised distance to a destination is lower that the router's Feasible Distance to that same destination. 3. Successor : The neighbor that has been selected as the next hop for a given destination based on the Feasibility Condition. Reference: Jeff Doyle, Routing TCP/IP, Volume I, Chapter 8: Enhanced Interior Gateway Routing Protocol (EIGRP), p.336-337, Cisco Press, (ISBN 1-57870-041-8) Additional info: The Feasible Condition is met when the receiving router has a Feasible Distance (FD) to a particular network and it receives an update from a neighbor with a lower advertised or Reported Distance (RD) to that network. The neighbor then becomes a Feasible Successor (FS) for that route because it is one hop closer to the destination network. There may be a number of Feasible Successors in a meshed network environment. The RD for a neighbor to reach a particular network must always be less than the FD for the local router to reach that same network. In this way EIGRP avoids routing loops. This is why routes that have RD larger than the FD are not entered into the Topology table. Reference: Ravi Malhotra, IP Routing, Chapter 4: Enhanced Interior Gateway Routing Protocol (EIGRP), O'Reilly Press, January 2002 (ISBN 0-596-00275-0)

QUESTION NO: 308 A router has learned three possible routes that could be used to reach a destination network. One route is from EIGRP and has a composite metr of 20514560. Another route is from OSPF with a metric of 782. The last is from RIPv2 and has a metric of 4. Which route or routes will the router install in the routing table? A. the OSPF route B. the EIGRP route C. the RIPv2 route D. all three routes E. the OSPF and RIPv2 routes

Answer: B

Which one of the following protocols allows the information about the configuration of a new VLAN to be distributed across entire switched network? A. STP B. VTP C. EIGRP D. SNMP E. CDP F. None of the above

Answer: B Explanation: Sybex CCNA Study Guide 4th Edition states on page 359: "The basic goals of VLAN Trunking Protocol (VTP) are to manage all configured VLANs across a switched internetwork and to maintain consistency throughout that network. VTP allows an administrator to add, delete, and rename VLANs-information that is then propagated to all other switches in the VTP domain." Incorrect Answers: A. STP is the Spanning Tree Protocol, used to prevent bridging loops in a LAN. C. EIGRP is a routing protocol used to exchange routing information, not VLAN information. D. SNMP is the Simple Network Management Protocol, used to provide information to remote network management stations. E. CDP is the Cisco Discovery Protocol, which is used to exchange information between Cisco devices. It can only be used between Cisco routers and switches.

Which two statements are true regarding EIGRP? (Choose two.) A. Passive routes are in the process of being calculated by DUAL. B. EIGRP supports VLSM, route summarization, and routing update authentication. C. EIGRP exchanges full routing table information with neighboring routers with every update. D. If the feasible successor has a higher advertised distance than the successor route, it becomes the primary route. E. A query process is used to discover a replacement for a failed route if a feasible successor is not identified from the current routing information.

Answer: B,E

Which routing protocols will support the following IP addressing scheme? (Choose three.) Network 1 - 192.168.10.0 /26 Network 2 - 192.168.10.64 /27 Network 3 - 192.168.10.96 /27 Network 4 - 192.168.10.128 /30 Network 5 - 192.168.10.132 /30 A. RIP version 1 B. RIP version 2 C. IGRP D. EIGRP E. OSPF

Answer: B,D,E Explanation: Section 12: Configure, verify, and troubleshoot OSPF (19 questions)

A routing protocol is required that supports: 1) routing update authentication 2) an addressing scheme that conserves IP addresses 3) multiple vendors 4) a network with over 50 routers Which routing protocol fulfills these requirements? A. RIPv2 B. RIPv1 C. OSPF D. EIGRP

Answer: C Explanation: EIGRP is CISCO private agreement, which will not support non-CISCO devices; RIPv1 and RIPv2 are distance vector protocol, supporting up to 15 hop, and 16 hop is inaccessible. RIPv1 does not support routing update verification. Although the convergence rate of OSPF is slower than EIGRP, but OSPF has better expansibility. And OSPF supports multi-vendor devices, and is applicable to large networks.

A mediumsized company has a Class C IP address. It has two Cisco routers and one nonCisco router. All three routers are using RIP version 1. The company network is using the block of 198.133.219.0/24. The company has decided it would be a good idea to split the network into three smaller subnets and create the option of conserving addresses with VLSM. What is the best course of action if the company wants to have 40 hosts in each of the three subnets? A. Convert all the routers to EIGRP and use 198.133.219.32/27, 198.133.219.64/27, and 198.133.219.92/27 as the new subnetworks. B. Maintain the use of RIP version 1 and use 198.133.219.32/27, 198.133.219.64/27, and 198.133.219.92/27 as the new subnetworks. C. Convert all the routers to EIGRP and use 198.133.219.64/26, 198.133.219.128/26, and 198.133.219.192/26 as the new subnetworks. D. Convert all the routers to RIP version 2 and use 198.133.219.64/26, 198.133.219.128/26, and 198.133.219.192/26 as the new subnetworks. E. Convert all the routers to OSPF and use 198.133.219.16/28, 198.133.219.32/28, and 198.133.219.48/28 as the new subnetworks. F. Convert all the routers to static routes and use 98.133.219.16/28, 198.133.219.32/28, and 198.133.219.48/28 as the new subnetworks.

Answer: D

A network administrator is troubleshooting an EIGRP problem on a router and needs to confirm the IP addresses of the devices with which the router has established adjacency. The retransmit interval and the queue counts for the adjacent routers also need to be checked. What command will display the required information? A. Router# show ip eigrp adjacency B. Router# show ip eigrp topology C. Router# show ip eigrp interfaces D. Router# show ip eigrp neighbors

Answer: D

QUESTION NO: 218 A mediumsized company has a Class C IP address. It has two Cisco routers and one nonCisco router. All three routers are using RIP version 1. The company network is using the block of 198.133.219.0/24. The company has decided it would be a good idea to split the network into three smaller subnets and create the option of conserving addresses with VLSM. What is the best course of action if the company wants to have 40 hosts in each of the three subnets? A. Convert all the routers to EIGRP and use 198.133.219.32/27, 198.133.219.64/27, and 198.133.219.92/27 as the new subnetworks. B. Maintain the use of RIP version 1 and use 198.133.219.32/27, 198.133.219.64/27, and 198.133.219.92/27 as the new subnetworks. C. Convert all the routers to EIGRP and use 198.133.219.64/26, 198.133.219.128/26, and 198.133.219.192/26 as the new subnetworks. D. Convert all the routers to RIP version 2 and use 198.133.219.64/26, 198.133.219.128/26, and 198.133.219.192/26 as the new subnetworks. E. Convert all the routers to OSPF and use 198.133.219.16/28, 198.133.219.32/28, and 198.133.219.48/28 as the new subnetworks. F. Convert all the routers to static routes and use 98.133.219.16/28, 198.133.219.32/28, and 198.133.219.48/28 as the new subnetworks.

Answer: D

QUESTION NO: 305 Refer to the exhibit. A network associate has configured the internetwork that is shown in the exhibit, but has failed to configure routing properly. Which configuration will allow the hosts on the Branch LAN to access resources on the HQ LAN with the least impact on router processing and WAN bandwidth? A. HQ(config)# router rip HQ(config-router)# network 192.168.2.0 HQ(config-router)# network 172.16.0.0 Branch(config)# router rip Branch (config-router)# network 192.168.1.0 Branch (config-router)# network 192.168.2.0 B. HQ(config)# router eigrp 56 HQ(config-router)# network 192.168.2.4 HQ(config-router)# network 172.16.25.0 Branch(config)# router eigrp 56 Branch (config-router)# network 192.168.1.0 Branch (config-router)# network 192.168.2.4 C. HQ(config)# router ospf 1 HQ(config-router)# network 192.168.2.4 0.0.0.3 area 0 HQ(config-router)# network 172.16.25.0 0.0.0.255 area 0 Branch(config)# router ospf 1 Branch (config-router)# network 192.168.1.0 0.0.0.255 area 0 Branch (config-router)# network 192.168.2.4 0.0.0.3 area 0 D. HQ(config)# ip route 192.168.1.0 255.255.255.0 192.168.2.5 Branch(config)# ip route 172.16.25.0 255.255.255.0 192.168.2.6 "

Answer: D Explanation: Static routes can be used to allow Branch LAN to access resources on the HQ LAN with the least impact on router processing and WAN bandwidth. Compared with dynamic routes, static routes have the following advantages: 1. Control 2. Easy configuration 3. Less WAN bandwidth

Which tables of EIGRP route information are held in RAM and maintained through the use of hello and update packets? (Choose two.) A. RTP table B. SPF table C. query table D. neighbor table E. DUAL table F. topology table

Answer: D,F Explanation: Only the neighbor table and the topology table of EIGRP route information are held in RAM and maintained through the use of hello and update packets.

15. Which two of the following commands will place network 10.2.3.0/24 into area 0? (Choose two.) A. router eigrp 10 B. router ospf 10 C. router rip D. network 10.0.0.0 E. network 10.2.3.0 255.255.255.0 area 0 F. network 10.2.3.0 0.0.0.255 area0 G. network 10.2.3.0 0.0.0.255 area 0

B, G. To enable OSPF, you must first start OSPF using a Process ID. The number is irrelevant; just choose a number from 1 to 65,535 and you're good to go. After you start the OSPF process, you must configure any network that you want advertised via OSPF using wildcards and the area command. Answer F is wrong because there must be a space after the parameter area and before you list the area number.

7. Which of the following protocols support VLSM, summarization, and discontiguous networking? (Choose three.) A. RIPv1 B. IGRP C. EIGRP D. OSPF E. BGP F. RIPv2

C, D, F. RIPv1 and IGRP are true distance-vector routing protocols and can't do much, really—except build and maintain routing tables and use a lot of bandwidth! RIPv2, EIGRP, and OSPF build and maintain routing tables, but they also provide classless routing, which allows for VLSM, summarization, and discontiguous networking.

5. Which command will display all the EIGRP feasible successor routes known to a router? A. show ip routes * B. show ip eigrp summary C. show ip eigrp topology D. show ip eigrp adjacencies E. show ip eigrp neighbors detail

C. Any secondary route to a remote network is considered a feasible successor, and those routes are only found in the topology table and used as backup routes in case of primary route failure. You can see the topology table with the show ip eigrp topology command.

12. For some reason, you cannot establish an adjacency relationship on a common Ethernet link between two routers. Looking at the output below, what is the cause of the problem? RouterA# Ethernet0/0 is up, line protocol is up Internet Address 172.16.1.2/16, Area 0 Process ID 2, Router ID 172.126.1.1, Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 172.16.1.2, interface address 172.16.1.1 No backup designated router on this network Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 RouterB# Ethernet0/0 is up, line protocol is up Internet Address 172.16.1.1/16, Area 0 Process ID 2, Router ID 172.126.1.1, Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 172.16.1.1, interface address 172.16.1.2 No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 A. The OSPF area is not configured properly. B. The priority on RouterA should be set higher. C. The cost on RouterA should be set higher. D. The Hello and Dead timers are not configured properly. E. A backup designated router needs to be added to the network. F. The OSPF Process ID numbers must match.

D. The Hello and Dead timers must be set the same on two routers on the same link or they will not form an adjacency (relationship). The default timers for OSPF are 10 seconds for the Hello timer and 40 seconds for the Dead timer.

4. Where are EIGRP successor routes stored? A. In the routing table only B. In the neighbor table only C. In the topology table only D. In the routing table and neighbor table E. In the routing table and the topology table F. In the topology table and the neighbor table

E. Successor routes are going to be in the routing table since they are the best path to a remote network. However, the topology table has a link to each and every network, so the best answer is topology table and routing table. Any secondary route to a remote network is considered a feasible successor, and those routes are only found in the topology table and used as backup routes in case of primary route failure.