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EIGRP Questions

July 10th, 2011 in ICND2 Go to comments

Here you will find answers to EIGRP Questions

Note: If you are not sure about EIGRP, please read my EIGRP tutorial

Question 1

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 metric 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

Explanation

Regardless of the metric value, EIGRP has the lowest Administrative Distance (AD) so it will be used and routes learned from EIGRP will be installed in the routing table. Some popular ADs are listed below:

+ Static route: 1
+ RIPv1 & RIPv2: 120
+ IGRP & EIGRP: 90
+ OSPF: 110

Question 2

HQ_Router# show ip protocols

Routing Protocol is “eigrp 109”
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Default networks flagged in outgoing updates
Default networks accepted from incoming updates
EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
EIGRP maximum hopcount 100
EIGRP maximum metric variance 1
Redistributing: eigrp 109
Automatic network summarization is in effect
Automatic address summarization: 20.0.0.0/0 for FastEthernet0/1
Summarizing with metric 28160 172.30.0.0/16 for FastEthernet0/0
Summarizing with metric 28160
Maximum path: 4
Routing for Networks:
20.0.0.0
172.30.0.0
192.160.1.0
Routing Information Sources:
Gateway Distance Last Update
20.10.10.2 90 260796
172.30.10.2 90 454765
Distance: internal 90 external 170

How many paths can the EIGRP routing process use to forward packets from HQ_Router to a neighbor router?

A. two equal-cost paths
B. two unequal-cost paths
C. three equal-cost paths
D. three unequal-cost paths
E. four equal-cost paths
F. four unequal-cost paths


Answer: E

Explanation

Because the “EIGRP maximum metric variance” is 1 so only equal-cost paths are used.
The “Maximum path” is 4 so EIGRP can use up to 4 paths to forward packets.

Therefore EIGRP can only use four equal-cost paths -> E is correct.

Notice: This question has another version with “EIGRP maximum metric variance” is set to a value greater than 1 than the answer should be “four unequal-cost paths” can be used.

Question 3

Fabrikant Incorporated is a worldwide finance provider. The network uses EIGRP as its routing protocol throughout the corporation. The network administrator does not understand the convergence of EIGRP. Using the output of the show ip eigrp topology all-links command, answer the administrators questions:

Switch1# show ip eigrp topology all-links

show_ip_eigrp_topology_all_links.jpg

Which three EIGRP routes will be installed for the 172.20.3.128 /25 and 172.20.2.0/24 networks? (choose three)

A. 172.20.3.128 /25 [90/28160] via 172.20.1.2 01:26:35. FastEthernet0/2
B. 172.20.3.128 /25 [90/30720] via 172.20.3.2 01:26:35. FastEthernet0/3
C. 172.20.3.128 /25 [90/30720] via 172.20.10.2 01:26:35. FastEthernet0/1
D. 172.20.2.0 /24 [90/30720] via 172.20.10.2 02:10:11. FastEthernet0/1
E. 172.20.2.0 /24 [90/28160] via 172.20.10.2 02:10:11. FastEthernet0/1
F. 172.20.2.0 /24 [90/33280] via 172.20.3.2 02:10:11. FastEthernet0/1


Answer: B C D

Explanation

There is a similar question posted at http://www.digitaltut.com/route-eigrp-simlet. Please read the explanation there and try to answer this question.

Question 4 (same question as question 3)

Switch1# show ip eigrp topology all-links

show_ip_eigrp_topology_all_links.jpg

Which three networks does the Switch1 device have feasible successors for? (Choose three)

A. 172.20.10.0 /30
B. 172.20.1.0 /24
C. 172.20.2.0 /24
D. 172.20.3.0 /25
E. 172.20.3.128/25
F. 10.69.0.0/24


Answer: A C F

Question 5

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 topology
B. Router# show ip eigrp interfaces
C. Router# show ip eigrp adjacency
D. Router# show ip eigrp neighbors


Answer: D

Explanation

Below is an example of the “show ip eigrp neighbors” command (from 9tut.com)

EIGRP_show_ip_eigrp_neighbors.jpg

Question 6

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 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.


Answer: A D

Question 7

Problems may occur when a routing protocol tries to identify the next hop in discontinuous networks in the IP addressing scheme. But some routing protocols may minimize the effects of the problems.

Which are these routing protocols? (Choose three)

A. EIGRP
B. VLSM
C. OSPF
D. RIP v2


Answer: A C D

Explanation

Classless routing protocols can be used in discontinuous networks as they do send the subnet mask in their updates so Variable Length Subnet Masks (VLSMs) are supported.

Question 8

Glencoe#show ip protocol
Routing Protocol is “eigrp 478”
β€” output omitted β€”
Redistributing: eigrp 478
Automatic network summarization is not in effect
Maximum path: 4
Routing for Networks:
172.26.168.128/26
172.26.169.0/26
Routing Information Sources:
Gateway Distance Last Update
172.26.168.129 90 01:01:59
Distance: internal 90 external 170

The EIGRP configuration in the Glencoe router uses a single network statement.
From the output shown in the graphic, which network statement would advertise these networks in EIGRP?

A. network 172.26.168.128 area 478
B. network 172.26.0.0
C. network 172.26.168.0 area 478
D. network 172.26.168.128 0.0.0.127


Answer: B

Question 9

What will a router do if it does not have EIGRP feasible successor route to a destination network and the successor route to that destination network is in active status?

A. It broadcasts Hello packets to all routers in the network to re-establish neighbor adjacencies.
B. It routes all traffic that is addressed to the destination network to the interface indicated in the routing table.
C. It sends a multicast query packet to all adjacent neighbors requesting available routing paths to the destination network.
D. It sends a copy of its neighbor table to all adjacent routers.


Answer: C

Question 10

The company uses EIGRP as the routing protocol.

EIGRP_show_ip_route.jpg

R3# show ip route
Gateway of last resort is not set
192 168.10.0/24 is variably subnetted, 6 subnets, 2 masks
D 192.168. 10.64/26 [90/2195456] via 192.168.10.9, 00:03:31, Serial0/0
D 192.168.10.0/30 [90/2681856] via 192.168.10.9, 00:03:31, Serial0/0
C 192.168.10.4/30 is directly connected, Serial 0/1
C 192.168.10.8/30 is directly connected, Serial 0/0
C 192.168.10.192/26 is directly connected, FastEthernet0/0
D 192.168.10.128/26 [90/2195456] via 192.168.10.5,00:03 31, Serial 0/1

What path will packets take from a host on 192.168.10.192/26 network to a host on the LAN attached to router R1?

A. The path of the packets will be R3 to R2 to R1.
B. The path of the packets will be R3 to R1 to R2.
C. The path of the packets will be both R3 to R2 to R1 and R3 to R1.
D. The path of the packets will be R3 to R1.


Answer: D

Explanation

From the line “D 192.168. 10.64/26 [90/2195456] via 192.168.10.9, 00:03:31, Serial0/0″ we can see the IP address 192.168.10.9 belongs to network 192.168.10.8/30 and this network is between R1 and R3 -> Packet from 192.168.10.192/26 network destined to a host on the LAN attached to router R1 will go directly from R3 to R1.

Comments (31) Comments
Comment pages
1 2 176
  1. Eddy
    May 16th, 2013

    for Q4, Dax explaination is the right one.

    Answer is C, E, F

  2. Anonymous
    May 22nd, 2013

    5, 6 and 10 where on the exam today

  3. Nate Johnson
    May 24th, 2013

    Had question 6 today

  4. ftreqah
    June 20th, 2013

    Q still valid Thanks 9tut passed today with 944. i had question 1,6,7,10 in the exam
    good luck

  5. jorge
    June 23rd, 2013

    Hello everybody,

    On friday i took my exam and i pass it, well the exam was really easy i just studied this tutorial and the lastes dumps.

    Find attached the link where you can find the latest dumps.

    http://www.examcollection.com/cisco/Cisco.ActualTests.640-802.v2013-01-28.by.Spike.662q.vce.file.html

    Be confident and believe yourself, if you had studied donΒ΄t be afraid and took it, i was afraid before took it but then i realized that everything i studied was in the exam.

    good luck on your exam!!! πŸ™‚ πŸ™‚ πŸ™‚

  6. Anonymous
    July 3rd, 2013

    Can somebody pls explain question 4 for me?

  7. JJ
    July 6th, 2013

    answer 4 explanation….

    A,C,F– two entries in the topology table ,two different metrics to reach the destination and relative distance is less then the feasible distance. therefore will have feasible successors routes to the destination network

  8. MO
    August 5th, 2013

    Just wrote my ICND2 today, and i got 902/1000.. Question 10 was in the exam.. Thanks to the 9tut team..

  9. Nimal
    August 25th, 2013

    I had a difficult time understanding Question 9. I thought why would the router look for feasible successor if it has another router in “active” state as mentioned above in Q9.

    Finally found out that it’s the topology table that lists it as “active” when it doesn’t have any Feasible successors to reach a network and the successor has gone down. then it keeps sending multicast queries to its neighbours trying to find a Feasible Successor. Found that proper explanation over here: https://learningnetwork.cisco.com/thread/47367

    hope this helps someone.

  10. John.J
    August 27th, 2013

    Attention!!!
    Question 1 explanation wrong:

    Administrative Distance of IGRP is 100 and is not as same as EIGRP.

    Thanks

  11. Nivi
    August 27th, 2013

    Question 10 is wrong. the answer is C when looking in the ip route there are 2 paths with the 2195456 cost so EIGRP will load balance the traffic equally across those links…:)

  12. Nivi
    August 29th, 2013

    never mind my above statement Q10 is 100% correct. cant delete posts :/

  13. thanh
    August 31st, 2013

    hihi everyboby !!
    all answer in the Q4 is wrong @@ do anyone agree with me ??????

  14. ftut
    September 2nd, 2013

    I agree that all answers in Q4 are wrong. Check out the FD vs AD for each. They are all the same and the AD must be < FD to become a feasable successor. Maybe it's the wrong screenshot of the routing table? There is a good explanation of a similar question here: http://www.digitaltut.com/route-eigrp-simlet

  15. bybytes
    September 3rd, 2013

    I agree with Nivi. C should be the answer for Question 10.

  16. Nimal
    September 3rd, 2013

    @Nivi, @bybytes, Gusy the answer for Question 10 is D as mentioned above.

    look closely at the routing table:
    192 168.10.0/24 is variably subnetted, 6 subnets, 2 masks
    D 192.168. 10.64/26 [90/2195456] via 192.168.10.9, 00:03:31, Serial0/0
    D 192.168.10.0/30 [90/2681856] via 192.168.10.9, 00:03:31, Serial0/0

    notice that the two routes are not equal cost routes to the same network!. Only the first route points to the 192.168.10.64/26 network that the packet wants to get to..

    It mentions that s0/0 is the interface that it should use. so looking a bit below in the routing table we see this connected subnet to s0/0:
    C 192.168.10.8/30 is directly connected, Serial 0/0

    and when we look at the diagram we see that 192.168.10.8/30 is between R3 & R1. So the packet simply can go from R3 -> R1.

    There is a variation of this same question where there are 2 equal cost paths to the subnet attached to R1. That’s where the answer ‘C’ becomes correct, but not in this case.

    Understand the concept well and you’ll be able to answer however it may come. easy..

  17. Router.Maestro
    September 8th, 2013

    Q4: Answer A is clearly WRONG. The RD must be strctly less than, NOT less than or equal to, the FD. For 172.20.10.0 /30 the FD = 20,514,560 (commas added for clarity of magnitude.) One link has RD = 20,514,560, equal to the FD. The other link has RD = 205,122,000, or an order of magnitude GREATER THAN the FD. There IS NO FS for this route. The correct answer, besides C and F, is E.

  18. kevin
    September 11th, 2013

    igrp ad is 100 not 90

  19. Traian
    September 11th, 2013

    Hi guys,
    related to question 4 .. it seems that all the 3 networks: 172.20.10.0 /30 , 172.20.2.0 /24, 10.69.0.0/24 have FD=AD . Regarding to this 9tut explanation http://www.digitaltut.com/route-eigrp-simlet , the networks with FD=AD can not have a feasible successor. Please somebody explain this. Thanks a lot.

  20. Ricky Bobby
    September 12th, 2013

    @Router.Maestro Answer A is correct. It cannot be Answer E because the two routes have the same metric and therefore will be load balanced, remember this is EIGRP which will load balance across 4 equal-cost links by default (i think it’s four).

    The FD of the first route under Answer A is 20514560 which is lower than the second route. Therefore it will be chosen as a Successor route with the second option being a Feasible Successor.

    Think I’m right here, been studying EIGRP for a while now ahead of my exam.

  21. Thyreme
    September 13th, 2013

    Q4 is correct!

  22. Me
    September 14th, 2013

    Q4 is wrongggggg……….!

    A. 172.20.10.0 /30 <— the RD of the second route is equal NOT lower!

    via 172.20.1.1 (FD1 / RD1)
    via 172.20.10.2 (FD2 / RD2)

    RD2 must be LOWER than FD1 to become a Successor. It shows RD2 = FD1 so it cannot be a Sucessor Route.

    The E is the only correct option because the second route has a RD lower than the first routes FD.

    Period.!

  23. Me
    September 14th, 2013

    Not even the E is correct because the metric is the same so the router will load balance the traffic between the 2, so I’m not sure if we can call it a FS route.

  24. Fel
    September 16th, 2013

    None of these were on the exam today. Passed with 916

  25. shonz
    September 17th, 2013

    hie guyz howz ccna

  26. BHN
    September 18th, 2013

    Q8: Can someone explain why answer is B? I have no idea why.

  27. TrickedbyCisco
    September 19th, 2013

    Fail. Took the supposed ICND2 640-816 today and there was nothing like the material contained on this site. No VTP, No VLSM, No Drags and Drop (except 1, had Split Horizon), no ACL or NAT. It was all about SNMP and Netflow. 2 Different SIMS OSPF and EIGRP (not on this site or dump) A lot IPV6. I nailed ICND1 exam but this wasnt the test I prepared for. Please reply.

  28. TrickedbyCisco
    September 20th, 2013

    For some reason my exam overlapped and I got 200-100. Didnt know was there already and Fail. 640-816 next Monday.

  29. Thyreme
    September 23rd, 2013

    @ BHN

    Because if we do turn the Auto summary on then it will advertise network 172.26.0.0 instead of 172.26.x.x when no Auto summary is on, because the first two octets will match and the rest don’t.

  30. Anonymous
    September 26th, 2013

    Q4 is correct.

    The question is asking which networks have a FEASIBLE SUCCESSOR. In the #show ip eigrp toplogy output, you are looking for an entry that has more next-hop address routes than there are successors.

    P 10.69.0.0/24, 1 successors, FD is 156160, serno 16
    via 172.20.3.2 (156160/128256), FastEthernet0/3
    via 172.20.10.2 (158720/156160), FastEthernet0/1

    Here, 1 successor is declared which is the “via 172.20.3.2…” route. Therefore, 10.69.0.0/24 has a feasible successor in the “via 172.20.10.2…” route.

  31. lopy
    October 15th, 2014

    Q9: i think it is B becouse ther are no information that the process are recalculate

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