Home > OSPF Sim


January 8th, 2015 in Lab Sim, LabSim Go to comments


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.


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 (the IP of interface S0/0 of Portland) belongs to. This address belongs to a subnetwork which has:

Increment: 4 (/30 = or 1111 1111.1111 1111.1111 1111.1111 1100)
Network address: (because 4 = 4 * 1 and 4 < 5)
Broadcast address: (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 (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 & The full command we use here is network 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 to join Area 1, notice that you have to convert subnet mask into wildcard mask:

Portland(config-router)#network area 1

Configure Portland as a stub:

Portland(config-router)#area 1 stub

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 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#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


Comment pages
1 2 3 84
  1. Need
    December 19th, 2017

    hi mkzozocan you please share the 470q dumps to me ppatra631(@)gmail

  2. Mac
    December 20th, 2017

    @ bloomingonion

    Thanks for the information you provided it really help me figure out what’s going on with this lab. It says use the most specific wildcard mask possible, the key word is “POSSIBLE” I was using the specific wildcard mask for a /30 because you can’t get any more specific than that, not realizing that I need to use a (possible) wildcard mask that will allow pings to traverse the network and it doesn’t have to be absolutely SPECIFIC as I was thinking.

    Thanks again you may have saved my score with that piece of information.

  3. 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

  4. Dexter
    December 27th, 2017

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

  5. 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….

    snt (at) g a z e t a . p l

  6. 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….

  7. 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 from Los Angles router.

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

    I configured Indianapolis as follow
    Network 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 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?

  8. 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
    It does the same thing activating the interface for hello messages.

  9. v1pz
    January 12th, 2018

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

  10. ali
    January 13th, 2018

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

  11. Anonymous
    January 21st, 2018

    @User did you passed the exam

  12. dumpspro
    January 26th, 2018

    latest ccie 400-101 dumps


  13. 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

  14. 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}


  15. Adnan
    April 2nd, 2018

    Hello to all !

    Please, can you send me the the 539q dumps ?

    My address email is adnan255 @ hotmail . com !

    Thank you for your support !!!

  16. Anonymous
    April 10th, 2018

    Hello to all !

    Please, can you send me the ccnp route last dumps ?

    My address email is {email not allowed}

    Thank you for your support !!!

  17. dannDumb
    April 11th, 2018

    Does anybody has the last dumb, my email is dani_giggles(@)hotmail.com

  18. cisco breaker
    April 11th, 2018

    Hello, I have all the latest dumps and labs.

    leonardocpereira94 @ gmail . com

  19. Elv
    April 16th, 2018

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

  20. Elv
    April 16th, 2018

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

  21. Elv
    April 16th, 2018

    But the overall solution is the same.

Comment pages
1 2 3 84
  1. No trackbacks yet.