Home > CCNA – OSPF Questions

CCNA – OSPF Questions

March 20th, 2011 Go to comments

Here you will find answers to OSPF Questions

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

Question 1

Which of the following statements below best describe the process identifier that is used to run OSPF on a router? (Choose two)

A – It is an optional parameter required only if multiple OSPF processes are running on the router
B – It is locally significant
C – It is needed to identify a unique instance of an OSPF database
D – All routers in the same OSPF area must have the same process ID if they are to exchange routing information


Answer: B C

Question 2:

Why R1 can’t establish an OSPF neighbor relationship with R3 according to the following graphic? (Choose two)

OSPFneighbor

A – Configure EIGRP on these routers with a lower administrative distance
B – All routers should be configured for backbone Area 1
C – R1 and R3 have been configured in different areas
D – The hello and dead interval timers are not configured the same values on R1 and R3


Answer: C D

Explanation:

A is not correct because configure EIGRP on these routers (with a lower administrative distance) will force these routers to run EIGRP, not OSPF.

B is not correct because the backbone area of OSPF is always Area 0.

C and D are correct because these entries must match on neighboring routers:

- Hello and dead intervals
Area ID (Area 0 in this case)
– Authentication password
– Stub area flag

Question 3:

Which items are correct about the routing protocol OSPF? (Choose three)

A – Support VLSM
B – Increase routing overhead on the network
C – Confine network instability to one area of the network
D – Allow extensive control of routing updates


Answer: A C D

Explanation:

Routing overhead is the amount of information needed to describe the changes in a dynamic network topology. All routers in an OSPF area have identical copies of the topology database and the topology database of one area is hidden from the rest of the areas to reduce routing overhead because fewer routing updates are sent and smaller routing trees are computed and maintained (allow extensive control of routing updates and confine network instability to one area of the network).

Question 4:

Which three features are of OSPF routing protocol? (Choose three)

A – Converge quickly
B – OSPF is a classful routing protocol
C – Identify the best route by use of cost
D – Before exchanging routing information, OSPF routers find out neighbors


Answer: A C D

Question 5:

OSPF routing uses the concept of areas. What are the characteristics of OSPF areas? (Chose three)

A – Each OSPF area requires a loopback interface to be configured
B – Areas may be assigned any number from 0 to 65535
C – Area 0 is called the backbone area
D – Hierarchical OSPF networks do not require multiple areas
E – Multiple OSPF areas must connect to area 0
F – Single area OSPF networks must be configured in area 1


Answer: B C E

Explanation:

I used to think the answers should be C D E and here is my explanation:

OSPF can use an active interface for its router ID, so a loopback interface is not a must -> A is incorrect.

OSPF Area is a 32-bit number so we can use up to 232 – 1 = 4294967296 – 1 (since Area 0 is the first area). Remember that only process ID is a 16-bit number and ranges from 1 to 65535 -> B is incorrect.

F is incorrect too because single area OSPF netwoks must be configured in Area 0, which is called the backbone area.

For answer D, it is a bit hard to guess what they want to say about “hierarchical” but we should understand “Hierarchical OSPF networks” as “OSPF networks”. D is correct bercause we can only have one area (area 0 – the backbone area) for our networks.

But TT commented on 01-11-2010:

Especially to note on choice B, D, and E:

Choice B: we all know that The areas can be any number from 0 to 4.2 billion and 1 to 65,535 for the Process ID. As choice B specifies ‘area’ (be aware, it’s not saying ‘process id), there is no reason to say that we cannot assign numbers from 0 to 65535 for area # (it is using ‘may be’, not ‘have to be’ or ‘ought to be’). Hence, we do not worry about assigning ’0′.

Choice E: as Area 0 is the backbone, we all understand that any areas in a OSPF network have to be connected to it. And actually this is implicitly saying that multiple areas form a hierarchical OSPF network, as Area 0 being a root and others being its leaves.

Choice D: when it specifies ‘Hierarchical’, at least 2 areas should be required to form such topology (of course that includes Area 0)

Although Choice B is not an absolutely accurate statement since it not only can be assigned up to 65535, it is still a correct answer. And again, it specifies ‘area’, not ‘process id’, so ’0′ can be included. Finally, it would be meaningless to call OSPF a hierarchical network if no more than one area is present.

—————————————————————————————————-

I reviewed the question and think it is a more suitable solution with choice B than choice D, surely it is a tricky question!

Question 6:

Part of the OSPF network is shown below:

OSPF_Routing

Configuration exhibit:

R1 routing commands:

ip route 0.0.0.0 0.0.0.0 serial0/0
router ospf 1
network 172.16.100.0 0.0.0.3 area 0
network 172.16.100.64 0.0.0.63 area 0
network 172.16.100.128 0.0.0.31 area 0
default-information originate

You work as a network technician, study the exhibits carefully. Assume that all router interfaces are operational and correctly configured. In addition, assume that OSPF has been correctly configured on router R2. How will the default route configured on R1 affect the operation of R2?

A – Any packet destined for a network that is not directly connected to router R2 will be dropped immediately
B – Any packet destined for a network that is not directly connected to router R1 will be dropped
C – Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1
D – The network directly connected to a router R2 will not be able to communicate with the 172.16.100.0, 172.16.100.28 and 172.16.100.64 subnetworks.
E – Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur


Answer: E

Explanation:

First, notice that the more-specific routes will always be favored over less-specific routes regardless of the administrative distance set for a protocol. In this case, because we use OSPF for three networks (172.16.100.0 0.0.0.3, 172.16.100.64 0.0.0.63, 172.16.100.128 0.0.0.31) so the packets destined for these networks will not be affected by the default route.

The default route configured on R1 “ip route 0.0.0.0 0.0.0.0 serial0/0″ will send any packet whose destination network is not referenced in the routing table of router R1 to R2, it doesn’t drop anything so answers A, B and C are not correct. D is not correct too because these routes are declared in R1 and the question says that “OSPF has been correctly configured on router R2″, so network directly connected to router R2 can communicate with those three subnetworks.

As said above, the default route configured on R1 will send any packet destined for a network that is not referenced in its routing table to R2; R2 in turn sends it to R1 because it is the only way and a routing loop will occur.

Comments
Comment pages
1 7 8 9 10 15
  1. Farhan
    April 15th, 2013

    passed icnd2 today and got Q6 in the exam … Thanks to 9tut and all people who share their information here.

  2. hatim
    April 21st, 2013

    Hey guys. please send me the latest dumps for CCNA. i am waiting for your responses:)
    helbinani.emi@gmail.com

  3. ccna beginer
    April 21st, 2013

    Hi 9tut

    what is this no auto summary for ospf ?
    if don’t for above command what do you suggest ?

  4. Rahul kumar
    April 21st, 2013

    how many attemp we have to write ccna exam on same fee?
    tell me if any body know that.

  5. Metal
    April 25th, 2013

    Q5 in my exam – correct answers B C E.
    Passed exam with score 1000/1000 so this answer is correct.
    TY 9tut.

  6. Nate
    May 14th, 2013

    To BobSmith: I believe since the default route from R1 is being propogated to R2 via OSPF default information originate, any route that R2 doesn’t have in the table will shoot over to R1, which will then cause a loop since the default route for R1 is already incorrect. Someone let me know if I’m wrong.

  7. mark
    May 17th, 2013

    at Q6..

    it will create a loop because the exit imterface used on default route is s0/0 . simple as that

  8. michael
    May 22nd, 2013

    preparing to take my ccna exam please can someone send me the latest dumps.
    mail:michael.wanjiru@gmail.com

  9. eitezaz
    May 22nd, 2013

    Going to attempt CCNA exam in coming week. Kindly someone send me the latest dumps
    mail: eitezaz_engr@yahoo.com

  10. malik
    May 22nd, 2013

    can someone email me the latest dumps. Also does anyone know when the CCNA exam is changing?
    shahram3272gmail.com

  11. mohamed
    May 23rd, 2013

    Please please please guys i am preparing for the exam next month, can someone be kind enough to send me the latest dumps on my e-mail : mastermalganis@hotmail.com

  12. Mohd
    May 24th, 2013

    Hi guys. Please send me the last dumps at mohammad_shihadeh@hotmail.com thanks

  13. David Okeri
    May 28th, 2013

    Pliz i will sit for the exam next month, can someone send me the latest dumps on email: olesimbe@yahoo.com

  14. musicmaakr
    May 28th, 2013

    Folks, after you get your CCNA, don’t forget to come back and donate. I just did. This is one of the most helpful websites on the net and deserves to be supported. Thanks 9tut!

  15. moe elppit
    May 28th, 2013

    i need a help i need latest ccna dump and i will appreciate that
    this is my email mca.1990@hotmail.com
    my exam is too close
    thanks guys

  16. Andrei G
    May 30th, 2013

    hi guys, I’m preparing for the CCNA exam next month, can someone be kind enough to send me the latest dumps on grosu29@yahoo.com
    Thank you!

  17. hemga
    June 11th, 2013

    for latest “pass4sure” CCNA and CCNP DUMP UPDATED WILL BE PROVIDED
    FOR CONTACT MAIL examsdump@gmail.com

  18. Priya
    June 14th, 2013

    i have my exam tmrw , will i have to pay for the other attempt if i fail at the first ?

  19. anny
    June 14th, 2013

    Hi All!

    Could anyone please explain why Router 2 in Q.6 doesn’t drop the packet but sends it back to R1. According to me, R2 should drop the packet for which it doesn’t have destination packet in its routing table. Explanation says otherwise. Also, split horizon prevents routing loops , so why loop occur at all.

    Thanks in advance.

  20. anny
    June 14th, 2013

    @Priya , all the very best for your exam. Don’t think about the result. Who know, tomorrow might be your best day. Give your best shot. God Bless You.

  21. anny
    June 14th, 2013

    or is it because a default route is configured ON R1 which is also known to R2, hence R2 sends the packet back to R1. Anyways, i would be glad if someone explains it succinctly.

  22. Ram
    June 14th, 2013

    Hello Priya, I hope you cleared the exam. Congratz. How was the exam? All the questions were from dumps? What are the SIM questions asked? I’m giving my exam on 17th Jun.

  23. Avinash Kumar
    June 24th, 2013

    Hi Anny,
    The routers are running OSPF and they are in area 0. Why split horizon will even come into play as that is for RIP.
    default-information originate will advertise the default route configured on R1 to R2 through the OSPF.
    Also, the rule of thumb for a default route is that this should be configured on stub.
    Ta
    Avinash

  24. Fatalay
    June 29th, 2013

    Hello,

    The comments and questions from this site has helpful, I will be taking the exam on the 1st July can someone show me link were I will get simulations

  25. Fatalay
    June 29th, 2013

    The comments and questions from this site have been helpful, I will be taking the exam on the 1st July can someone show me a link were I will get simulations

  26. kash
    July 3rd, 2013

    ALHUMDOLILLAH
    Thanks GOD I pass today. I recommend spike dump, 9tut, and for Urdu students urduitacademy.com. All questions came from spike dump and labs from 9tut. Thanks spike, 9tut and Mr. Kashif from urduitacademy…any query —> ks_jafry@yahoo.com

  27. Manoj Diora
    July 4th, 2013

    HEY GUYS

    IS ANY BODY CAN SEND ME LATEST DUMP CCNA PLEASE.MY EMAIL IS manoj0601@yahoo.com

  28. augusto
    July 12th, 2013

    split horizon, impede que atualizações sejam mandadas pela mesma interface, mas no caso o router 1 tem uma rota default para o router 2, criando um lacete

  29. Anonymous
    July 15th, 2013

    Question 5:
    B – Areas “may be assigned any number” from 0 to 65535
    which is valid within the “area range”

  30. Rich
    July 19th, 2013

    For reference, I got this from the CCNA Lab guide.

    OSPF does not support the auto-summary feature, so the auto-summary command is rejected.

  31. Vinoymarz
    July 23rd, 2013

    Please send me a latest dump on mervs00024@yahoo.com. planning to take exam on august 2013.. thanks in advance

  32. Temzeg
    July 26th, 2013

    I am taking the exam (CCNA) next week can someone send me the latest dump to my e-mail temzeg@yahoo.com thank you so much for your help

  33. Rose
    July 26th, 2013

    hi! I will take exam 2nd week of August, can someone send me the latest dump. my email is rosecrene@gmail.com . thank you very much in advance.

  34. ahmed sheikh
    July 28th, 2013

    can any one please send me latest ccna dumps i am taking ccna exam soon your help is appriciated

  35. ahmed sheikh
    July 28th, 2013

    can any one please send me latest ccna dumps i am taking ccna exam soon your help is appriciated

    ahmedfaaf@hotmail.co.uk

  36. jojo
    July 30th, 2013

    thx

  37. DUMPS
    July 30th, 2013

    Kindly send me latest CCNA Dumps to mmanzur2005@gmail.com

  38. Regis
    July 31st, 2013

    Hi guys. Please send me the last dumps at jesse712@hotmail.com
    I am studying for CNNA and will take it next month
    thx

  39. ICND2-or-Bust
    July 31st, 2013

    The answer above is valid only if you assume R2 has a default route pointing to R1. That is kind of hinted at in the explanation: “…R2 in turn sends it to R1 because it is the only way…”.

    But, of course, any time you have two routers pointing default routes at each other, a big alarm bell should go off in your head.

  40. J M
    August 1st, 2013

    @ICND2-or-Bust

    There are no assumptions as R1 is configured with “default-information originate” meaning it will advertise its configured default route to other routers. Since it’s default route is the interface that connects R2 any unknown traffic will create a routing loop.

  41. Mizhi
    August 5th, 2013

    Hey Guys,

    Can some one please mail the latest CCNA Dumps to mizhi24@gmail.com.
    Also wuld like to take some advice from people who have recently given their exams. Did u guys get any questions from Netflow or any other new topics and question on frame relay which u haven’t seen before ? If yes then please give us a brief idea about as to what were the questions framed like.
    Thanks in Advance. :)

  42. JBS
    August 7th, 2013

    Wish you luck, tomorrow is the day! :-)

  43. ceceenea
    August 7th, 2013

    Can someone kindly send me the latest IDND2 or CCNA dump? taking the test in a week… ceceenea@hotmail.com Thank you much!

  44. patriq kajawoh
    August 8th, 2013

    i will write my ccna in next week can someone kindly send me the latest dump plz i beg pkajawoh@gmail.com

  45. chanaka
    August 11th, 2013

    r u mad Oakley Asian Fit Lunettes de soleil

  46. Fernando E
    August 19th, 2013

    To clear something about Q5:
    Areas may be assigned any number from 0 to 4294967295.
    Anyways i think the answer B is correct because the range 0 to 65535 is inside whole range.

  47. Adeel
    August 26th, 2013

    Hello Guys I hope you will be fine there. I have CCNA (640-802) and CCNA security (640-554) Vouchers on special discount of 58% for World wide, with six months expiry date till you purchase. Each voucher cost 70USD.
    Details Required For CCNA Voucher For Discount Processing:
    1-Full Name. 1st Name & Last Name (as you want to appear on certificate & documents)
    2-Country.
    3-City.
    4-State.
    5-Pin Code (or Area Code)
    6-Residential Address (or where you can collect your Certificate or further correspondence
    can be received)
    7-Date of birth
    Add me on Skype through this information which is written below:
    Skype Name: rockon660
    you can also email me at this email address which is written below:
    madeelqaiser@gmail.com
    If you have any Questions feel free to contact me.
    Thanks,
    Best regards,
    Adeel

  48. Juliano
    August 27th, 2013

    Please please please guys i am preparing for the exam next month, can someone be kind enough to send me the latest dumps on my e-mail : spyderjas@gmail.com

  49. hozyfa
    September 1st, 2013

    hi guys my exam in next week please send my the last dumps hozyfa_it@yahoo.com

  50. Max
    September 3rd, 2013

    Can somebody plz send me the latest dumps for CCNA .
    i have an exam on the 23 of September.
    email address is marjans1985@yahoo.com

    Thanks

Comment pages
1 7 8 9 10 15
  1. No trackbacks yet.
Add a Comment