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EIGRP Stub Sim

July 31st, 2010 in LabSim Go to comments

Question

By increasing the first distant office, JS manufactures has extended their business. They configured the remote office router (R3) from which they can reach all Corporate subnets. In order to raise network stableness and lower the memory usage and broadband utilization to R3, JS manufactures makes use of route summarization together with the EIGRP Stub Routing feature. Another network engineer is responsible for the implementing of this solution. However, in the process of configuring EIGRP stub routing connectivity with the remote network devices off of R3 has been missing.

EIGRPStubSim

Presently JS has configured EIGRP on all routers in the network R2, R3, and R4. Your duty is to find and solve the connectivity failure problem with the remote office router R3. You should then configure route summarization only to the distant office router R3 to complete the task after the problem has been solved.

The success of pings from R4 to the R3 LAN interface proves that the fault has been corrected and the R3 IP routing table only contains two 10.0.0.0 subnets.

Answer and Explanation:

First we have to figure out why R3 and R4 can not communicate with each other. Use the show running-config command on router R3

EIGRPStubSim_show_running_config_R3

Notice that R3 is configured as a stub receive-only router. The receive-only keyword will restrict the router from sharing any of its routes with any other router in that EIGRP autonomous system. This keyword will also prevent any type of route from being sent.

Therefore we will remove this command and replace it with the eigrp stub command:

R3#configure terminal
R3(config)#router eigrp 123
R3(config-router)#no eigrp stub receive-only
R3(config-router)#eigrp stub
R3(config-router)#end

Now R3 will send updates containing its connected and summary routes to other routers. Notice that the eigrp stub command equals to the eigrp stub connected summary because the connected and summary options are enabled by default.

Next we will configure router R3 so that it has only 2 subnets of 10.0.0.0 network. Use the show ip route command on R3 to view its routing table

R3#show ip route

EIGRPStubSim_show_ip_route_R3_no-summary.jpg


Because we want the routing table of R3 only have 2 subnets so we have to summary sub-networks at the interface which is connected with R3, the s0/0 interface of R4.

There is one interesting thing about the output of the show ip route shown above: the 10.2.3.0/24, which is a directly connected network of R3. We can’t get rid of it in the routing table no matter what technique we use to summary the networks. Therefore, to make the routing table of R3 has only 2 subnets we have to summary other subnets into one subnet.

In the output if we don’t see the summary line (like 10.0.0.0/8 is a summary…) then we should use the command ip summary-address eigrp 123 10.2.0.0 255.255.0.0 so that all the ping can work well.

In conclusion, we will use the ip summary-address eigrp 123 10.2.0.0 255.255.0.0 at the interface s0/0 of R4 to summary.

R4>enable
R4#configure terminal
R4(config)#interface s0/0
R4(config-if)#ip summary-address eigrp 123 10.2.0.0 255.255.0.0

Now we jump back to R3 and use the show ip route command to verify the effect, the output is shown below:

EIGRPStubSim_show_ip_route_R3_final_no_summary.jpg

(But please notice that the ip addresses and the subnet masks in your real exam might be different so you might use different ones to solve this question)

But in your real exam, if you see the line “10.0.0.0/8 is a summary,….Null0″ then you need to summary using the network 10.0.0.0/8 with the command “ip summary-address eigrp 123 10.0.0.0 255.0.0.0″ . This configuration is less optimize than the first but it summaries into 2 subnets as the question requires (maybe you will not see this case, don’t worry!).

The command “copy running-config startup-config” will not work so try using this command; just skip if it doesn’t work.


Other lab-sims on this site:

OSPF Sim

EIGRP OSPF Redistribution Sim

IPv6 OSPF Virtual Link Sim

EIGRP Simlet
Policy Based Routing Sim

Comments
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  1. fulltimes
    August 12th, 2011

    are you know V200?

  2. Anonymous
    August 22nd, 2011

    i am know V200

  3. Anonymous
    August 22nd, 2011

    pls does anyone know V200

  4. Anonymous
    August 23rd, 2011

    Good News !!!
    I have a updated dump contact me for it
    kellysmith114@gmail.com

  5. promise2k
    September 1st, 2011

    hi all
    i cleared my route exam today. The Labs were – EIGRP – OSPF Redistribution Sim – Policy Based Routing Sim – IPv6 OSPF Virtual Link Sim – OSPF Sim

  6. Mohamed Sabry
    September 8th, 2011

    I Passed yesterday with score 965 , thanks guys and digitaltut :) all labs from here

  7. all4u
    September 10th, 2011

    http://www.4shared.com/file/MNxMccev/GNS3_642-902_Test_Sims.html

    all labs from digitaltut.com in GNS3 format with IOS. Its not my work, i am just sharing

  8. gillman
    September 12th, 2011

    For the summary address on R4 why use the whole 10.2.0.0 network range?? why not use summary address 10.2.0.0 255.255.240.0 which covers 10.2.0.0-10.2.15.254?? this also leaves two subnet in the routing table of R3

  9. onecutebreezy
    September 13th, 2011

    Pls can anyone send me a copy of the latest CCNP Route dumps to my email: onecutesoul@hotmail.com
    I will really appreciate it. Am kinda confused and dont knw how to get it at the moment.

  10. Dharsh
    September 16th, 2011

    just passed with 976. tnx digitaltut and all

  11. ccnp_hopeful
    September 17th, 2011

    @gillman:

    Sham
    February 5th, 2011

    @ Swetha
    If you use mask 255.255.0.0 you are advertising the whole class B block which is not wrong but not the most optimized summary, because that way R4 will advertises 10.2.0.0 – 10.2.255.0 although it only knows about 10.2.2.0-10.2.9.0 networks.

    But if you use 255.255.240.0 mask. R4 will advertise only 10.2.0.0 – 10.2.15.0 networks only. Which is more specific than the previous case.That is the only difference.

    In both cases, the routing table will have 2 subnets, so no harm done and both methods will follow the required criteria.

    But personally I use 255.255.240.0 because that’s the best practice.
    Hope this helps.

  12. Mohammad
    September 20th, 2011

    @All

    When summarizing the networks 10.2.2.0 – 10.2.9.0 in R3 routing table I came with the summary 10.2.2.0/20. Is it wrong? and how the summary address 10.2.0.0 255.255.0.0 was obtained in the shown solution.

    Can anyone explain it more for me?

    Thanks

  13. agent_07
    September 22nd, 2011

    @ mohammad

    if you put on s 0/0 your proposed summary address, you will also have the same output as the sim is requiring but if you look on the routing table you will get this output..

    Gateway of last resort is not set

    172.16.0.0/24 is subnetted, 1 subnets
    C 172.16.1.0 is directly connected, FastEthernet0/0
    10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    D 10.2.0.0/20 [90/2195456] via 10.2.3.4, 00:00:07, Serial0/0
    C 10.2.3.0/24 is directly connected, Serial0/0

    As you see, your summary address did not appeared because the right summary address is 10.2.0.0/20, it is from 10.2.0.0-10.2.15.0. In other words, you put an address within the range.

  14. Mohammad
    September 23rd, 2011

    @agent_07

    Thank you for ur reply.

    I think both solutions would work. bcuz ur summarized address gives another range that encompasses the routing table subnets, it will contain the range from 10.2.0.0 – 10.2.15.255 but mine will include the range from 10.2.2.0 – 10.2.17.255. So in both cases the addresses are included.

    But when checking other exams I saw a proposed solutions of 10.0.0.0/8 and 10.2.0.0/16 as a summary. But these subnets include many addresses which I think is not accurate. Will they accept any of these solutions? or which solution is the best to stick with?

    Thanks again mate :)

  15. lat
    September 26th, 2011

    Please can anyone help on site like this for switching

  16. aftershocks
    October 1st, 2011

    Hi Mohammad,

    I’m with ya on this.. I came up with a summary address of 10.2.2.0/21… The address they used to summarize would work also, but it’s summarizing a huge range of address which is not “efficient”…

    Wouldn’t 10.2.2.0/21 work also? but when I enter that in, “ip summary-address eigrp 123 10.2.2.0 255.255.248.0″, I get these routes:

    10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
    D 10.2.8.0/24 [90/2323456] via 10.2.3.4, 00:01:11, Serial0/0
    D 10.2.9.0/24 [90/2323456] via 10.2.3.4, 00:01:11, Serial0/0
    D 10.2.0.0/21 [90/2195456] via 10.2.3.4, 00:00:05, Serial0/0
    C 10.2.3.0/24 is directly connected, Serial0/0

    Can someone please tell me why the summary address remains 10.2.0.0/21 and not 10.2.2.0/21 as I specifically stated in the command?

    Is this because 255.255.248.0 looks at the first two octec. . .t . . . ohhhhhh. . .. . I get it now… :D

    nevermind, Thanks!

  17. man o
    October 4th, 2011

    is this stll valid please am writing my route exam on friday. please help.

  18. Wunz
    October 5th, 2011

    man o.. keep in faith… so do i.. i’ll take my exam friday… good luck for us… :)

  19. lil_wagon
    October 9th, 2011

    The “ip summary-address eigrp 123″ command can be simply summarized as “ip summary-address eigrp 123 10.0.0.0 255.0.0.0″. The question clearly states to reduce R3′s routing table to 2 “10.0.0.0″ subnets. This accomplishes that without complication. The end result is that traffic bound for any 10 network will be routed to R4 which has the more specific route to the given destination. There’s no need to be “efficient” in this case as R3 is a stub router and only has one way out.

    The other ways mentioned would work to route traffic as needed, but Cisco may ding you points for not being exact with their specification in the question. They didn’t say 2 subnets of “10.2.2.0″ or “10.2.0.0″.

  20. Mustafa
    October 17th, 2011

    Thank you very much

  21. Mustafa
    October 17th, 2011

    @all4u
    Thank man

  22. Adnan
    October 23rd, 2011

    Hi,

    I have 2 questions.

    1. at R3 we have seen no auto-summary commands is configured already and in EIGRP network if summary is configured at any point whole AS will see it as Summary address ( we have already mentioned that 10.0.0.0/8 is summary by using no auto-summary command) then why we have used ip summary-address command on R4 s0/0 interface.

    2).

    why we use summary on s0/0 of R4 ? why did not used at F0/0 ?

    Thanks.

  23. zshan
    October 25th, 2011

    @adnan..
    the ip summary-address command is specific to eigrp sub commands thats y we are using (if I understand ur question correctly) as there is no other way to summarize the routes.
    second we cannot use the summray on FE just because the R3 is rec these routes from the R4s s0/0 interface (you can verify it from the ip route command above as well, yes if it was recieving it from e0/0 then sure y not use that (but not practical).

  24. bangz
    October 27th, 2011

    hello guys. are these lab sim still valuable, is there anyone who just took the exams? please tell me, i have to take my exams soon,

  25. ali
    November 1st, 2011

    is the same ip in the exam or another one

  26. Bglr
    November 2nd, 2011

    Passed today with 965/1000 , all simulation are from digitaltut exactly , still REV7 is tottaly valid 100 % .. 2 new question MCQ , simulations are OSF,IPV6,Redistribution ,PBR .

    Thanks to digitaltut and all of you those who posted comments here….
    Really its great site……cheers…

  27. Anonymous
    November 4th, 2011

    can somebody please share the .pkt files if you have? Thanks in advance

  28. 4real
    November 18th, 2011

    Thanks to Digitaltut. I passed my ccnp route with 925 the day b4 yesterday (16/11). The labs were the same but few changes in IP adds, router names/locations. For those that are yet to take, this is d right site for u. Pls understand and concentrate on the given parameters.

    This particular lab was not given to me but I worked on eigrp ospf red sim, ospf sim, ipv6 ospf virtual link sim & policy based routing sim. Good-luck.

  29. ajith
    November 21st, 2011

    we can use effective summarization 10.2.0.0 255.255.240.0 coz 4 bits in 3rd octect are same for all route

  30. blackcisco
    November 30th, 2011

    @All

    Did anyone noticed that in the picture network 10.2.3/-24 is connected to s0/0 but in the output it says directly connected to s0/1. very starange isn’t t.

    FYI @Mohammed and @gillman u dont use wildcard mask in the summary address, just normal subnet mask

  31. Anonymous
    December 1st, 2011

    I;m confused if this LAB is included in the exam? Please confirm

  32. VoVa
    December 2nd, 2011

    It was not included in my exam today.

  33. pam
    December 4th, 2011

    hello all

    i cleared the exam with 930/1000. this was not in my exam today.. except this all the sims were there.. same concept but IPs were different

    gud luck for all

  34. Wolf
    December 8th, 2011

    Wrote ROUTE today…sim not in exam…there was a mcq based roughly on “eigrp stub recieve only”

  35. Anonymous
    December 10th, 2011

    so this exam EIGRP Stub Sim is not included in the real exam right guys?

  36. Mustafa
    December 10th, 2011

    Hi, get the same result with different configuration

    just write on R3
    R3(conf-route)#no eigrp stub reci
    R3(conf-route)#eigrp stub

    and on R4 write

    R4(conf-route)#eigrp stub

    then you will get the following on R3

    R3#sho ip rout

    Gateway of last resort is not set

    172.16.0.0/24 is subnetted, 2 subnets
    C 172.16.1.0 is directly connected, Loopback0
    C 172.16.2.0 is directly connected, Loopback1
    10.0.0.0/24 is subnetted, 2 subnets
    D 10.2.2.0 [90/2195456] via 10.2.3.4, 00:10:57, Serial0/0
    C 10.2.3.0 is directly connected, Serial0/0

    is that correct or I’m missing sth?

  37. jlv
    December 12th, 2011

    Hello Mustafa,

    If u configure R4 as stub, it will only adv eigrp routes connected and summary (default options). So in R3′s routing table networks 10.2.x.x other than 10.2.2.x and 10.2.3.x are missing. That is not the purpose of the question although it ends up with only two 10.x.x.x routes.

    BR

  38. P4S
    December 20th, 2011

    thanks for the confirmation guys… so this LAB is not included in the actual exam. cheers!

  39. Pradeep
    December 21st, 2011

    Gateway of last resort is not set

    172.16.0.0/24 is subnetted, 2 subnets
    C 172.16.1.0 is directly connected, Loopback0
    C 172.16.2.0 is directly connected, Loopback1
    10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    D 10.2.0.0/16 [90/2195456] via 10.2.3.4, 00:00:07, Serial0/0
    C 10.2.3.0/24 is directly connected, Serial0/0

    I’m getting the output as above, i’m unable to get the 172.16.0.0/24 as only one subnet as shown above.

    Am I doing it wrong?

  40. Danny
    December 22nd, 2011

    @Pradeep Those are you Loopback interfaces… read up a little on summarization and it will clear up… memorization will fog your mind.

  41. syed
    December 29th, 2011

    HI all i will write exam tomorrow who passed the exam please tell me that is there any new lab.

  42. VED
    December 29th, 2011

    Hi All

    I passed the exam today !!! Many of You know Me Last time When I passed The CCNA exam I remember All the Question and i send to you all also and its very helpfull to U all !!! Dont Worry Friends this time Also I remember All the Question !!! In exam I got 50 question

    Out of that three are Similator
    2 drag and drop

    Friends Any one Want the Question Please Update the Mail Id Or Send the Mail to the mail id : dononearth0@gmail.com ( as u know )

    Better U send the Mail So that I can Quick reply to You All

    Help other God will help You !!!

    Ur Friend Ved Prakash INDIA

  43. zakaryae
    December 30th, 2011

    Hi All4u

    thanks for sharing the GNS3 files, but what is the secret for “policy based routing” sim ?

    Regards

    zakaryae

  44. BLIKVI
    January 3rd, 2012

    Friends, how many hotspots are in the exam ? and could anyone share it ?

    Thank you in advance

  45. Khijir@huawei
    January 4th, 2012

    Dear all4u!!!!

    Thanks a million.
    Your topo is so helpful.
    Great effort for our learning.

  46. s s s
    January 5th, 2012

    THANK YOU SHAHID to share me latest dump, i passed yesterday i used dumps nonentity.338q.vce or actual test v 6.2 all questions from those dumps those are 100% valid and sims are from digitultut.com same sims only ip address and are change,4 sims ( Eigpr and ospf redistribute / ospf stub / ipv6 virtual-link / pbr ) and read question carefully.
    latest dumps actual test v 6.2 link http://www.4shared.com/office/J1iP8WU_/642-902.html .

  47. Ahmed
    January 7th, 2012

    Some ppl report getting all 5 SIMs in real exam, but most ppl report not getting this EIGRP Stub SIM. Commit it to memory just in case.

  48. codex
    January 9th, 2012

    in summary i think the optimal solution :

    R4(config-if)#ip summary-address eigrp 123 10.2.0.0 255.255.240.0

  49. Mirza
    January 13th, 2012

    in real exam (I mean GNS3) when you enter ip summary-address eigrp 1 10.2.0.0 255.255.240.0 or ip summary-address eigrp 1 10.2.0.0 255.255.0.0 or ip summary-address eigrp 1 10.0.0.0 255.0.0.0 in every case it will show you :

    10.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
    D 10.2.0.0/16 [90/2681856] via 10.2.3.4, 00:01:04, Serial2/0
    D 10.0.0.0/8 is a summary, 00:00:29, Null0
    C 10.2.3.0/24 is directly connected, Serial2/0

  50. D.S Tanwar
    January 17th, 2012

    hey Aftershocks
    U r getting confused in the summarization because if u summarize it as you did
    like 10.2.2.0 255.255.248.0
    will come in the range of 10.2.0.1 – 10.2.7.254 address
    and if u wanna summarize 16- bit subnet then u just have to apply ip summary-address eigrp 123 10.2.0.0 255.255.240.0
    This will summarize address 0f range 10.2.0.1 – 10.2.15.254

  51. Sir Klah
    January 18th, 2012

    Hello Friends,

    I just started to study the ROUTE test after taking almost two years off from passing the CCNA. I am planning to take the ROUTE test in two months. Are the Sims, Drag and Drop, Questions, and everything else on this site still valid for the ROUTE test?

    Thank you all!

  52. Jorge Allen Adajar
    January 26th, 2012

    @Mirza,
    i beleived that you need to type the “no auto-summary” in R3 to eliminate the Null0.. and the result needs to be like this:

    Gateway of last resort is not set

    172.16.0.0/24 is subnetted, 1 subnets
    C 172.16.1.0 is directly connected, FastEthernet0/0
    10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    D 10.2.0.0/20 [90/2681856] via 10.2.3.2, 00:02:36, Serial0/0
    C 10.2.3.0/24 is directly connected, Serial0/0

  53. caljacuto
    January 26th, 2012

    Passed 930/1000 Took exam 2 hrs ago, sims were IPV6 Virtual Link, Redistribution, Policy Based Routing, and EIGRP stub, no simlett or hotspot one D&D and a whole lot of questions not on this site. I got about 10 questions related to BGP that I had never seen before. Know your BGP is my recommendation.

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