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OSPF Questions 2

November 4th, 2018 Go to comments

Question 1


In IPv6, you can configure many address prefixes on an interface. In OSPFv3, all address prefixes on an interface are included by default. You cannot select some address prefixes to be imported into OSPFv3; either all address prefixes on an interface are imported, or no address prefixes on an interface are imported.

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/15-sy/iro-15-sy-book/ip6-route-ospfv3.html

Question 3

Question 4


Because the destination of is not present in the routing table so this router would use the default route (O*E2) to forward this packet. Usually the O*E2 is the result of the “default-information originate” command on the upstream router.

Question 5

Question 6


Before you enable OSPF for IPv6 on an interface, you must perform the following:

+ Complete the OSPF network strategy and planning for your IPv6 network. For example, you must decide whether multiple areas are required.
+ Enable IPv6 unicast routing.
+ Enable IPv6 on the interface.

Reference: https://www.cisco.com/c/en/us/support/docs/ip/ip-version-6-ipv6/112100-ospfv3-config-guide.html

Note: If we have already had an active interface, we don’t need to configure the router ID for OSPFv3 anymore because the device will automatically choose that IPv4 address for its router ID).

Question 7

Question 8


Hierarchical design of OSPF (basically means that you can separate the larger internetwork into smaller internetworks called areas) helps us create a network with all features listed above (decrease routing overhead, speed up convergence, confine network instability to single areas of the network).

Question 9

Question 10


To form an adjacency (become neighbor), router A & B must have the same Hello interval, Dead interval and AREA number.

Question 11

Question 12

Comments (21) Comments
  1. nickaro
    September 12th, 2017

    In Q4 is included in route So packets are sent to out interface Fa1/1. Am I right?

  2. nickaro
    September 20th, 2017

    I’ve just realized of my mistake. Destiny IP is, not :-(

  3. Tech Explorer
    December 27th, 2017

    Answer to question 6 is wrong. Right answer is:

    if ipv4 address does NOT exist: configure router id
    if ipv4 address does exist: no need to configure router id

    Source: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipv6/configuration/xe-3s/ipv6-xe-36s-book/ip6-ospf.html#GUID-C38CCDD0-560F-4CD2-A199-13930C6B0FE9

  4. mm
    January 10th, 2018

    Answer to Q6 should be D and E because we dont need to configure router id as the router already configured for ipv4.

  5. sachu
    January 11th, 2018

    Question 6 – How do we create IPv4 router id ? you have to configure it inside the ipv6 router ospf 1 !that means while your creating the ospv3 process. The question is” Before ” you implement ospfv3. so the correct answer would be E- enable ipv6 unicast routing and D- Enable IPv6 on an interface

  6. sadhu
    January 15th, 2018

    Question 6 – discard the previous post

  7. Come on
    January 26th, 2018

    If two OSPF neighbors have formed complete adjacency and are exchanging link-state advertisements, which state have they reached?
    A. Exstart
    B. 2-Way
    C. FULL
    D. Exchange
    the answer is D,,,
    the question is clearly saying are exchanging not done exchanging!
    if it was done exchanging then Full which is C

  8. DELES
    February 14th, 2018

    @come on: exchange is not a valid OSPF state, is part of the relation forming process. Full is the correct answer here.

  9. Jezzerman
    March 6th, 2018

    Question 10 does not give enough information. The configurations are missing

  10. Roman
    March 23rd, 2018

    Q5. DELES, exchange is a totally valid OSPF state which described in RFC 2328 10.1.
    There is a link: https://www.ietf.org/rfc/rfc2328.txt

    But yes, in exchange state routers are sending Database Description packets to the neighbor, but no more (I do not quite understand whether the LSR transmission is also in the state of Exchange or not. In any case there are no any fully LSAs.).

    So the only right question is FULL. I guess “are exchanging link-state advertisements” words refer to new changes in a network.

  11. Shariq
    May 9th, 2018

    are these OSPF eigrp questions includes sim questions as well ?? do i have to perform the practical or can i just select the right answer if i already know the answer because of dumps .

  12. albama
    June 9th, 2018

    Q3 is correct ? Or answer correct is C. Configure an IPv4 address on interface Fa0/0 beacause said ospf no ospfv3.

  13. Bisscay
    June 11th, 2018

    @Come on, the answer is FULL, not because of what @DELES says, exchange is actually a valid OSPF state, but because neighbors have formed complete adjacency which only occurs at FULL state. At EXCHANGE, database data is transferred but adjacency is not complete (routers have not converged)

  14. quantisol
    July 20th, 2018

    please i need dump questions.. on ospf

  15. quantisol
    July 20th, 2018

    am writing next week quantisol 4 at gmail.com

  16. Zee95
    October 14th, 2018

    Q3??? how is the answer A? if the destination ip address is not known the router will drop the packet! right??

  17. nhokthach123
    June 9th, 2019

    why i cant see the question ? can someone explain to me. Thanks you

  18. Yachiyo
    June 30th, 2019

    Q1 explanation should be in Q2 as Q1 is about Link-state protocols. Please fix.

  19. ali
    September 6th, 2019


  20. Sam
    October 17th, 2019

    I cant see any Question or answers. I can just see he Explanations… Whats wrong there

  21. totoro
    January 23rd, 2020


    Maybe I dont understand because of my poor english.. Why the answer is full state?

    1. Routers have formed complete adjacency and ARE exchanging LSAs.
    2. It doesnt say they have formed FULL ADJACENCY.
    3. Exchanging LSAs is not equal exchanging LSDB.
    4. They could be 2-way DRothers exchanging LSA packets.

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