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OSPF Sim

January 8th, 2019 in Lab Sim, LabSim Go to comments

Question

OSPF is configured on routers Amani and Lynaic. Amani’s S0/0 interface and Lynaic’s S0/1 interface are in Area 0. Lynaic’s Loopback0 interface is in Area 2.

OSPFSim

Your task is to configure the following:

Portland’s S0/0 interface in Area 1
Amani’s S0/1 interface in Area 1
Use the appropriate mask such that ONLY Portland’s S0/0 and Amnani’s S0/1 could be in Area 1.
Area 1 should not receive any external or inter-area routes (except the default route).

Answer and Explanation:

First, we configure Portland’s S0/0 interface so that it belongs to Area 1. So, we have to find out which sub-network the IP address 192.168.4.5/30 (the IP of interface S0/0 of Portland) belongs to. This address belongs to a subnetwork which has:

Increment: 4 (/30 = 255.255.255.252 or 1111 1111.1111 1111.1111 1111.1111 1100)
Network address: 192.168.4.4 (because 4 = 4 * 1 and 4 < 5)
Broadcast address: 192.168.4.7 (because 7 = 4 + 4 – 1) (It is not necessary to find out the broadcast address but we should know it)

The question requires that only Portland’s S0/0 and Amani’s S0/1 could be in Area 1, therefore we must use a wildcard of 0.0.0.3 (this wildcard is equivalent with a subnet mask of /30) so that there are only 2 IP addresses can participate in area 1 (they are 192.168.4.5 & 192.168.4.6). The full command we use here is network 192.168.4.4 0.0.0.3 area 1

The question also requires that “Area 1 should not receive any external or inter-area routes (except the default route)”. Recall that if we don’t want the router to receive external routes, we have to stop LSA Type 5. And if we don’t want to receive inter-area routes, we have to stop LSA Type 3 and Type 4. Therefore we have to configure area 1 as a totally stubby area. For your information, here is the definition of a totally stubby area:

Totally stubb area – This area does not accept summary LSAs from other areas (types 3 or 4) or external summary LSAs (Type 5). Types 3,4 and 5 LSAs are replaced by the Area Border Router(ABR) with a default router. Totally stubby areas protect internal routers by minimizing the routing table and summarizing everything outside the area with a default route.” (CCNP BSCI Official Exam Certification Guide, Fourth Edition)

In conclusion, we have to configure area 1 as a totally stubby area. We do that by configuring Portland as stub and configuring Amani (ABR router) as a stub + “no-summary”suffix.

+ Configure Portland router as a stub:

Portland#configure terminal
Portland(config)#router ospf 1

Allow network 192.168.4.4/30 to join Area 1, notice that you have to convert subnet mask into wildcard mask:

Portland(config-router)#network 192.168.4.4 0.0.0.3 area 1

Configure Portland as a stub:

Portland(config-router)#area 1 stub

Portland(config-router)#end
Portland#copy running-config startup-config

+ Configure Amani router as a “totally stub”:

Amani#configure terminal
Amani(config)#router ospf 1
Amani(config-router)#network 192.168.4.4 0.0.0.3 area 1

Make area 1 become a totally stubby area, notice that we can only use this command on ABR router:

Amani(config-router)#area 1 stub no-summary

Amani(config-router)#end
Amani#copy running-config startup-config

Note: Make sure to check the OSPF process ID before typing your configuration. Maybe it is not OSPF process 1 like the configuration above.

 

Other lab-sims on this site:

EIGRP Stub Sim

EIGRP OSPF Redistribution Sim

IPv6 OSPF Virtual Link Sim

EIGRP Simlet
Policy Based Routing Sim

 

Comments
Comment pages
  1. Mac
    December 20th, 2017

    Ok that wildcard mask is not longer working for me, I don’t know if its the lab or just the config but i’ll try it on the exam either way

  2. Dexter
    December 27th, 2017

    Mac, he is talking for Redistribution lab and you for OSPF

  3. Przemek
    January 3rd, 2018

    Hi everybody!
    I’m going to pass 23th of January 2018. All is paid.
    Please :-)… send me newest dumps you have….

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  4. Anonymous
    January 6th, 2018

    Hi everybody!
    I’m going to pass 23th of January 2018. All is paid.
    Please :-)… send me newest dumps you have….

  5. User
    January 11th, 2018

    I was asked to create Area 2 and add Los Angles and Indianapolis routers and make them Stub Areas both with OSPF ID 75 on all the routers. Then I was asked I should be able to ping New York router loopback address 172.16.237.237 from Los Angles router.

    I configured Los Angles router as follow
    Router ospf 75
    Network 192.168.46.44 0.0.0.3 Area 2
    Area 2 Stub
    Copy Run St

    I configured Indianapolis as follow
    Network 192.168.46.44 0.0.0.3 Area 2
    Area 2 Stub no-Summary
    Copy Run St

    I was not able to ping loopback 0 or New York router. I used show Ip interface Brief on New York router only had serial interface configured. So no loopback 0 was configured, I tried to configure the loopback 0 172.16.237.237 on New York router the router would not let me do it when I tried config t was getting pop up “the configuration has been locked on this router”.

    Why Cisco asked me to ping a loopback address if it is not configured at all and why it would not let me add the loopback address which is missing to the New York router?

  6. v1pz
    January 12th, 2018

    To be honest you dont need to find out the wildcard mask.
    you can just to with the ip address on the interface and wildcard mask of 0.0.0.0
    It does the same thing activating the interface for hello messages.

  7. v1pz
    January 12th, 2018

    I guess this is an extra “cisco” question lol, in the real world I would never do that..

  8. ali
    January 13th, 2018

    can any one explain please how can we measure network ip ??

  9. Anonymous
    January 21st, 2018

    @User did you passed the exam

  10. dumpspro
    January 26th, 2018

    latest ccie 400-101 dumps

    dumpspro.com/ccie-dump

  11. Shri
    February 21st, 2018

    Hi guys any latest dumps for 300-101.

    my exam is in next month.

    this is my email id :- shriramtrimal19 at gmail dot com

    thank you

  12. JL
    March 29th, 2018

    Hi gents ,

    How can I open the labs with GNS3 ? the extension of all this labs is .net and I’m not able to open it .

    Please help..

    May e-mail is {email not allowed}

    Thanks
    JL

  13. Adnan
    April 2nd, 2018

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    April 10th, 2018

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  15. dannDumb
    April 11th, 2018

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  16. cisco breaker
    April 11th, 2018

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  17. Elv
    April 16th, 2018

    Routers use different name. They are not exactly the same as the one’s in this site.

  18. Elv
    April 16th, 2018

    Routers use different names. They are not exactly the same as the one’s in this site.

  19. Elv
    April 16th, 2018

    But the overall solution is the same.

  20. unstoppable
    April 27th, 2018

    @Elv,

    whats the wildcard mask need to use?
    I don’t understand what people talking about the wildcard mask need to be in 0.0.0.7 for router Lynaic?

  21. 1w4n
    April 30th, 2018

    @unstopable not sure myself. Just labbed it in gns and loopback on Lynaic is pingable with wildcard mask of 0.0.0.3

  22. Lipa
    June 3rd, 2018

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  23. Anonymous
    June 3rd, 2018

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  24. Mo
    July 2nd, 2018

    I failed today by 11 marks. The dumps are not helping. At more. So many new questions. This i site needs to be updated .

  25. renan
    July 20th, 2018

    @MO sad , what dumps you use?

  26. Bukaino
    August 7th, 2018

    I just passed ccnp switch 300-101 today 856
    I have the following sim
    -ospf sim
    -eigrp sim
    -ipv6 ospf
    -eigrp ospf redistribution

    send me mail if you need help

  27. AL
    August 8th, 2018

    Took 300-101 today and got a 768!!
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    email me {email not allowed}

  28. AL
    August 8th, 2018

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  29. FIFA
    August 9th, 2018

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  30. Anonymous
    August 15th, 2018

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  31. Twitter Duo
    August 18th, 2018

    i did pass the CCNP ROUTE 300-101 yesterday, 8xx/1000.
    There were a couple of new questions i did meet. 2 new drag and drop questions and 1 sim question. email me kiptalam54 at gmail dot com

  32. Anonymous
    August 18th, 2018

    @twitter duo did uh use the digitaltut dump for the exam

  33. kwatoniners
    August 21st, 2018

    @digitaltut. Is it a requirement in the exam to be able to ping 239.239.239.239 from portland router?
    Because I could ping the Serial interface of Lynaic router from Portland Rtr but not it’s loopback.
    Hope someone answers this question. thank you….

  34. mike
    September 10th, 2018

    Hello,

    Why on Portland we use only “stub” keyword, while on Amani we use “stub no-summary”?

  35. Cisco engineer
    September 10th, 2018

    Could somebody send me actual question to sys.yuriy at gmail.com.
    Thanks a lot.

  36. Cisco engineer
    September 10th, 2018

    Hi.
    Somebody could send me actual question to sys.yuriy at gmail.com.
    Thanks a lot.

  37. Arroyo Grande
    September 18th, 2018

    Hi, unfortunately I have failed the exam. Used the pass4sure material that can be renamed to fail4sure! If you are thinking on purchase these material, you better think twice.

    The labls are quite the same. Just do the labs from here and you will be ready to do the labs in the real exam.

    There are a lot of questions related to Frame-relay LMI, NAT-PT, NAT64, ACLs , A/A/A, mGRE, uRPF loose/strict and EVN.

  38. Steven
    September 19th, 2018

    @mike Because you only define the totally from the ABR. The other routers in a stub area doesn’t have to know this.

  39. @@@@
    October 1st, 2018

    Also dont buy dumps on certbus

  40. vasily
    October 11th, 2018

    can confirm that a lot of questions in Frame-relay LMI, NAT-PT, NAT64, ACLs , A/A/A, mGRE, uRPF loose/strict and EVN, debugging, logging configuration details, there was no question on OSPF, EIGRP, RIP routing specifics

    as for this lab, the most specific mask is 0.0.0.0, the lab itself is full of bugs, try to be as concise as possible

  41. Anonymous
    October 11th, 2018

    Hi everybody!
    I’m going to pass 23th of January 2018. All is paid.
    Please :-)… send me newest dumps you have…
    {email not allowed}

  42. Anonymous
    October 11th, 2018

    Hi everybody!
    I’m going to pass 20th of october 2018. All is paid.
    Please :-)… send me newest dumps you have….
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  43. ALNIR
    October 14th, 2018

    @steven
    if i don’t configure portland area 1 as stub with the “no-summary” command
    i cant see the default route in “show ip route”

    Portland#show ip route
    Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
    D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
    N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
    E1 – OSPF external type 1, E2 – OSPF external type 2
    i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
    ia – IS-IS inter area, * – candidate default, U – per-user static route
    o – ODR, P – periodic downloaded static route

    Gateway of last resort is not set

    192.168.4.0/30 is subnetted, 1 subnets
    C 192.168.4.4 is directly connected, Serial0/0
    Portland#

    instead with “no-summary”…

    Portland#show ip route
    Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
    D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
    N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
    E1 – OSPF external type 1, E2 – OSPF external type 2
    i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
    ia – IS-IS inter area, * – candidate default, U – per-user static route
    o – ODR, P – periodic downloaded static route

    Gateway of last resort is 192.168.4.6 to network 0.0.0.0

    192.168.4.0/30 is subnetted, 1 subnets
    C 192.168.4.4 is directly connected, Serial0/0
    O*IA 0.0.0.0/0 [110/65] via 192.168.4.6, 00:00:00, Serial0/0
    Portland#

    so what is the correct setting for portland stub configuration ???

  44. Espeon
    October 17th, 2018

    Today i failed exam, and score was 747. I’m not a native english speaker, sorry for my bad english skill.
    I didn’t prepared enough for test but i sure that you can pass with nneettwwoorrkkiinngg dump(u can pass with only ‘august’ section) and sim guide on digitaltut.
    I missed two configuration.
    1. EIGRP OSPF redistribution Sim
    – On my test, R2-R3 interface was fastethernet interface. So I tried to input command ‘distance eigrp 90 105’ in R2. But it didn’t work.
    I realized after test that the command must input on router-config mode. Now I know that is important to memorize exact router to input command.

    2. OSPF Sim
    – I had to intput area 1 stub on the Portland router and area 1 stub no-summary on the Amamni router. But I forgot and just advertised network. How foolish…

    And some of MCQ in dump has wrong answer. You can find it if you read the sentences observantly.
    I will try one more time on next week. Good luck for every task taker.

  45. EasyRider
    October 22nd, 2018

    What is the check of this lab?
    Which addresses we can ping from Portland? And which cannot?
    I think we can ping only Portland’s own interface and Amani’s s0/1 interface, am I right?
    And there is an incorrect IP address on the picture. We cannot use 239.239.239.239/32 address, because this is a multicast IP address. In the config file, which you can download is the correct address, which is 10.239.239.239/32.

  46. Espeon
    October 24th, 2018

    Hi, friends! I just passed exam with 856. 195(august) is still valid. But as I commented a weeks ago, there were several wrong answer in dump. You need to distinguish them before take exam. Accuracy is almost 90~95% I think.

    MCQ & DND
    – Just study 195 questions. Other sections are invalid.

    Sim
    – Redistribution, Virtual-link, EIGRP stub presented. PBR is not valid anymore in my opinion. I failed twice before pass, but PBR sim wasn’t present every time. Commands below are my summary note for Sim and may help your test.

    [EIGRP OSPF Redistribution]
    R2#show int s0/0/0
    (R2-R4 interface)

    router os 1
    re ei 100 metric- 1 subnets
    router ei 100
    re os 1 met 1544 2000 255 1 1500
    (serial int=1544)
    distance ei 90 105
    (Interface between R2 and R3 was Fastethernet on my test)

    R3#show int f0/0
    router os 1
    re ei 100 metric- 1 subnets
    router ei 100
    re os 1 metric 100000 10 255 1 1500
    (fa int=100000)

    [EIGRP Stub]
    R3#sh run
    (check ‘eigrp stub receive-only’ )

    R3#router eigrp 123
    no eigrp stub receive-only
    eigrp stub
    end

    R4#int s0/0
    ip sum eigrp 123 10.2.0.0 255.255.0.0
    (Interface between R3 and R4)

    [IPv6 OSPF Virtual Link]
    R2#ipv router os 1
    ar 11 vir 3.3.3.3

    R3#ipv router os 1
    no ar 54 vir 4.4.4.4
    ar 11 vir 2.2.2.2

    R4#ipv router os 1
    no ar 54 vir 3.3.3.3

    [OSPF]
    Portland#router ospf 1
    net 192.168.4.4 0.0.0.3 ar 1
    ar 1 stub

    Amani#router ospf 1
    net 192.168.4.4 0.0.0.3 ar 1
    ar 1 stub no

    Good luck for every test-takers.

  47. Anon
    October 28th, 2018

    Hi everyone, in this lab they ask specifically to configure:
    Portland’s S0/0 interface in Area 1 and Amani’s S0/1 interface in Area 1, why they are not doing it in the resolution?

    shouldn’t we add them?

    Portland:
    #int se0/0
    #ip ospf 1 area 1

    Amani:
    #int se0/1
    #ip ospf 1 area 1

    DO WE HAVE TO DO THIS ON THE EXAM!!!???

  48. Cool_guy
    October 28th, 2018

    Anon, no, because in exam you will have something like this: Routing protocol for each interface must be enabled under routing process. So you need to use “network” command.

  49. Networks
    November 2nd, 2018

    Today’s exam 834 score, Lab eigrp – ospf – redistribute-Drag – Drops Frame-Relay – GRE – Trafic

  50. Team_Stark
    December 9th, 2018

    HEY GUYS!
    I have a CCNP ROUTE DUMPS(SEPTEMBER 28 2018 UPDATED)

    LET’S TRADE! I NEED THE LATEST CCNA R&S DUMPS!
    EMAIL ME FIRST THE DUMPS AT THE FOLLOWING EMAIL:
    darksidius101(at)gmail(dot)com

    I WILL CHECK IT AND REPLY TO YOU BEFORE SATURDAY(Dec. 17, 2018)

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