Home > ICND2 – OSPF Questions 2

ICND2 – OSPF Questions 2

April 23rd, 2015 in ICND2 200-101 Go to comments

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

Question 1

Explanation

The output of the “show ip ospf database” is shown below:

show_ip_ospf_database.jpg

From the output above we can see LSA Type 1 (Router Link State) and LSA Type 3 (Summary Net Link State).

Question 2

Question 3

Explanation

There are 2 segments on the topology above which are separated by Corp-3 router. Each segment will have a DR so we have 2 DRs.

To select which router will become DR they will compare their router-IDs. The router with highest (best) router-ID will become DR. The router-ID is chosen in the order below:

+ The highest IP address assigned to a loopback (logical) interface.

+ If a loopback interface is not defined, the highest IP address of all active router’s physical interfaces will be chosen.

In this question, the IP addresses of loopback interfaces are not mentioned so we will consider IP addresses of all active router’s physical interfaces. Router Corp-4 (10.1.40.40) & Branch-2 (10.2.20.20) have highest “active” IP addresses so they will become DRs.

Question 4

Explanation

The default number of equal-cost paths that can be placed into the routing of a Cisco OSPF router is 4. We can change this default value by using “maximum-paths” command:

Router(config-router)#maximum-paths 2

Note: Cisco routers support up to 16 equal-cost paths

Question 5

Explanation

The highest IP address of all loopback interfaces will be chosen -> Loopback 0 will be chosen as the router ID.

Question 6

Explanation

A loopback interface never comes down even if the link is broken so it provides stability for the OSPF process (for example we use that loopback interface as the router-id) -> B is correct.

The router-ID is chosen in the order below:

+ The highest IP address assigned to a loopback (logical) interface.
+ If a loopback interface is not defined, the highest IP address of all active router’s physical interfaces will be chosen.

-> The loopback interface will be chosen as the router ID of RouterB -> C is correct.

Question 7

Explanation

The question states that the link to ISP should not participate in OSPF -> answers A, B are not correct.

In answer D, the “network 10.10.2.32 0.0.0.31 area 0” does not cover the IP address of S0/0.103 (10.10.2.21) -> D is not correct.

The default-information originate command advertises a default route to other routers, telling something like “please send me your unknown traffic”. So in this case, besides a full routing table, other routers will also receive a default route from Core router.
But please notice that Core router needs to have a default route in its routing table. That is why the command “ip route 0.0.0.0 0.0.0.0 10.10.2.14” is added to Core router. By adding the “always” (after “default-information originate” command) the default route will be advertised even if there is no default route in the routing table of router Core.

Question 8

Explanation

The “network 192.168.12.64 0.0.0.63″ equals to network 192.168.12.64/26. This network has:
+ Increment: 64 (/26= 1111 1111.1111 1111.1111 1111.1100 0000)
+ Network address: 192.168.12.64
+ Broadcast address: 192.168.12.127
Therefore all interface in the range of this network will join OSPF -> B C D are correct.

Comments (46) Comments
  1. Eddis
    December 21st, 2013

    Question 3 above is a duplicate of question 7 from ” New ICND2 – OSPF Questions “.

  2. Aspire
    April 9th, 2014

    Hi, can someone explain question 7 please?

  3. mike
    April 11th, 2014

    @aspire…

    Q7 – you want all subnets in your network to be included in the “network” command, except for the 10.10.2.13/30 for the internet connection…

    on Answer C, network 10.10.2.16 with a w/c mask of 0.0.0.15 (the same as a s/n mask of 255.255.255.240) includes all addresses from 10.10.2.16 – 10.10.2.31

  4. mike
    April 14th, 2014

    Took ICND2 earlier today, 986 / 1000.

    Questions 3 and 5 from this page were on there.

  5. Anthony
    April 16th, 2014

    Thanks for all your input and test followup comments Mike!

  6. sami
    April 26th, 2014

    hi all
    subscribe to that channel http://www.youtube.com/user/Joynetworks for free
    thanks

  7. tito
    April 30th, 2014

    hi aspire,
    q7 is subnetting at work. answer “c” encompasses the 2 networks of fa0/0 and s0/0.103. note that we have to exclude s0/1 as directed.

  8. fez
    May 8th, 2014

    3 and were there

    Passed today my ICND@2 by 1000. Got different configuration of the Eigrp & frame Relay labs where there were different DLCIs and IP addresses, but same process was used to get answers (show commands, show ip protocols, show ip interface brief ).

    A question about GLBP and a question about netflow were on my test. You can find them here: http://www.examtut.com/2013/09/new-questions-in-ccna-200-120-hsrp-vrrp.html

    Study 9tut and this guy i found him really helpful. He has unique way of teaching http://www.danscourses.com If you can do all his videos again and again. Trust me you will get the concept. Also one thing i learned today is if you don’t know the concept it’ll be hard for you in the exam.

    All the best to every one in their path. Keep me in your good wishes.

  9. izzarazzu
    June 8th, 2014

    Question 2.

    D ok, but why B and not E?

  10. izzarazzu
    June 27th, 2014

    Took the exam today. Pass 986/1000. Q3, Q5 were on there.
    Thanks 9tut.

  11. SlimyCheesePuff
    July 31st, 2014

    @izzarazzu

    E. the large size of the >>topology table<< listing all advertised routes in the converged network

    OSPF for IPv4 does not have topology tables. EIGRP is the interior gateway protocol that uses topology tables to determine a feasible successor.

  12. Ant
    August 20th, 2014

    Tested today, 8/20. #4, 5, 6 and 7 were on there.

  13. Georges
    September 27th, 2014

    took the exam today and pass with 907. Question 3 through 7 were on there, (#5 had only 1 loopback address).

    location United States Florida.

    test ICND 2

    Thanks 9tut

  14. Da Phaggot
    September 29th, 2014

    Havent taken the test yet

  15. Gary
    November 2nd, 2014

    Can someone explain question 8?
    what does this statement mean: The “network 192.168.12.64 0.0.0.63″ equals to network 192.168.12.64/26??

    Thank you.

  16. FLO
    November 3rd, 2014

    Gary, ” Its the network range of 192.168.12.64 0.0.0.63. So the Network is 192.168.12.64 and the Broadcast is 192.168.12.127 everything has to be in between 64 – 127. The 0.0.0.63 is the wildcard mask which OSPF uses. YOUTUBE Wildcard Mask for OSPF if you still dont get it.

  17. Gary
    November 4th, 2014

    FLO, Thanks, That makes sense!!

  18. Tshepo S Ndou
    December 1st, 2014

    There’s a question on ospf where u not allowed to view configs but u must answer five questions on it please assist if someone so it

  19. Tshepo S Ndou
    December 1st, 2014

    icnd 2

  20. Techgique
    February 6th, 2015

    Easiest way to look at wildcard masks if you are familiar with your normal masks is to just subtract the number from 255.

    So if we have 0.0.0.63 :

    255
    – 63
    ——–
    =192

    Now it looks likes a .192 mask, which we know has a 64 address subnet range (0-63, 64-127, 128-191, 192-255) When dealing with these familiar masks we can more easily determine the range of the subnet.

    Look at another:

    0.0.0.3 :

    255
    – 3
    ——-
    =252

    .252 mask has four addresses per subnet (0-3, 4-7, 8-11, 12-15, etc)

    Hope this helps

  21. stevy0
    February 14th, 2015

    Techgique makes a good point. Also another good tip for wildcards is to add 1 to the number to get the network increment. Take for example 0.0.0.3 – add 1 and we get 4. We know the increment is 4, which is correct as this is 255.255.255.252

  22. someone
    February 19th, 2015

    What’s the difference between OSPF v2 & OSPF v3 ?

    new Question .

  23. Mateus_Ben
    February 27th, 2015

    Q2:

    D – I get it;

    B – Why??? Isn’t “E” a better answer?

  24. Nic
    March 1st, 2015

    @someone
    You said that there is a new question :What’s the difference between OSPF v2 & OSPF v3 ?
    Can you still remember some of the different options of your exam?

  25. purna
    March 10th, 2015

    @Mateus_Ben
    Someone already pointed out>>>topology table<<< is an eigrp thingy and in ospf context, it should called "ospf database"

    Topology table is not like a registered trade mark of EIGRP, I am still thinking E is a better answer in a broad perspective.
    B. the requirement for a hierarchical IP addressing scheme for optimal functionality
    This sounds to me kind of a best practice for any routing routing protocol

  26. Montasir Osman
    March 19th, 2015

    Q 3,6 and 7 was there

  27. Caudrick
    April 1st, 2015

    Hi, please someone can explain me questions 8 ?

  28. preptotest
    April 15th, 2015

    @Caudrick
    for Q8 the advertised network is “City(config-router)# network 192.168.12.64 0.0.0.63 area 0”
    the wildcard mass 0.0.0.63 means to use increments of 64, so starting from 192.168.12.64 any IP with-in the next 64 bits will be advertised in OSPF. So 192.168.12.64 – 192.168.12.127 will be good because .128 will start the next subnet. It’s basically a part subnetting question.

    A trick I learned from a CBTnuggets with Keith Barker. for using wildcard mass is to just subtract 1 away from the subnet masks increment
    example: 128 64 32 16 8 4 2 1 (these are the increments for each subnet)
    128 192 224 240 248 252 254 255 (these are all possible subnet mask)
    if an ACL calls for us to only permit host 192.168.1.17 – 192.168.1.31 on 192.168.1.0/24 network
    we will use access-list 1 permit 192.168.1.16 0.0.0.15 any
    only 16 IP’s starting from 192.168.1.16 will be permitted. Hope this helped.

  29. preptotest
    April 15th, 2015

    after I submitted the comment it re-formatted it a little so I’m just sending this for more clarity
    128 64 32 16 8 4 2 1 (these are the increments for each subnet)
    128 192 224 240 248 252 254 255 (these are all possible subnet mask)

  30. Cos
    April 18th, 2015

    I had a question about the database exchange process: ExStart–>Exchange–>Loading–>Full

  31. JB
    April 28th, 2015

    Q4: in the explanation it states “Note: Cisco routers support up to 6 equal-cost paths”. It should be 16, not 6.

  32. 9tut
    April 28th, 2015

    @JB: Thanks for your detection. We have just updated it.

  33. Marco
    May 13th, 2015

    I got Q4, Q5, Q6, Q7 today in my ICND2 exam.
    Thanks 9tut.

  34. Grisha82
    June 22nd, 2015

    Got just Q4 today.

  35. mike
    June 23rd, 2015

    one question!!!
    who can help me?

    Given the show ip protocols how many ospf neighbors douse this router have?

    HICKORY#show ip protocols
    Routing Protocol is “ospf 1”
    Sending updates every 0 seconds
    Invalid after 0 seconds, hold down 0, flushed after 0
    Outgoing update filter list for all interfaces is
    Incoming update filter list for all interfaces is
    Redistributing: ospf 1
    Routing for Networks:
    0.0.0.0
    Routing Information Sources:
    Gateway Distance Last Update
    10.255.255.1 110 00:07:52
    Distance: (default is 110)

  36. Anonymous
    June 26th, 2015

    guys download dumps with nuggets free from this following link
    wurl. cc/dumps

  37. Anne Normous
    July 1st, 2015

    Just took the test today – 980/1000 Altrhough I did not get any questions from this page Q7 with different values was one of the questions in the OSPF sim. Thanks 9tuts! Also got Frame Relay, EIGRP and OSPF labs

    THERE IS NO NEED FOR ANY DUMPS – just study one book (Wendel or Todd) and the you tube lessons available free for visual knowledge. Along with 9tuts these are enough for 900 and over marks with ease.

    But you MUST understand the concepts and not mug up the answer as they change the options and answers

  38. aman
    July 6th, 2015

    Very good site for studying ccna. really good job

  39. 9tut
    July 13th, 2015

    @all: We had to move all the questions and answers out of 9tut. We can only keep the explanation. You can download the questions and answers at: https://mega.co.nz/#!oIdESYbD!yyu33vygrfKPy4rcmcbV6qW2fxINNoTokuDM3CjA_og

  40. Adan
    July 22nd, 2015

    why can’t I see the actual questions only the answers shown?

  41. canyouread?
    July 26th, 2015

    @Adan is exactly why so many people need to come here to find the answers. They won’t even take 2 seconds to look for an answer to their question that is RIGHT ABOVE THEIR POST.

  42. Anonymous
    July 28th, 2015

    Hey Guys,

    Question 3 I thought was E & F, because its the highest IP Address is there any reason why its not? Can someone please explain. Thanks

  43. Anon D
    August 13th, 2015

    @Anonymous,

    There can only be one DR for EVERY SEGMENT. The key to this question is to realise that there are 2 (LAN) segments. The first consists of Corp1, 2, 3 and 4. The second segment consists of Branch 1 and 2.

    Once you realise this, we can easily find out the DR for segment 1 is Corp-4 (highest IP in THAT segment) and the DR for segment 2 is Branch-2 (highest IP in THAT segment).

    Hence, answers D and F are correct. Hope this helps.

    Also been explained in the OSPF section of ICND1 if that helps. Good luck with your studies and exams!

  44. Anon33
    September 30th, 2015

    @ someone in FEB. David answered your question in March over in OSPF Questions 1

    What are two enhancements that OSPFv3 supports over OSPFv2? (Choose two.)
    A. It requires the use of ARP.
    B. It can support multiple IPv6 subnets on a single link.
    C. It supports up to 2 instances of OSPFv3 over a common link.
    D. It routes over links rather than over networks.
    Answer: B, D

  45. Anonymous
    October 14th, 2015

    Passed with 894 today. One question involves why two OSPF neighbors are stuck in EXSTART state. The answer is the MTU settings mismatch.

  46. adiboy
    June 22nd, 2016

    why there is no question showing ?