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IPv6 OSPF Virtual Link Sim

May 8th, 2018 in Lab Sim, LabSim Go to comments


TUT is a small company that has an existing enterprise network that is running IPv6 OSPFv3. However, R4’s loopback address (FEC0:4:4) cannot be seen in R1. Identify and fix this fault, do not change the current area assignments. Your task is complete when R4’s loopback address (FEC0:4:4) can be seen in the routing table of R1.


Special Note: To gain the maximum number of points you must remove all incorrect or unneeded configuration statements related to this issue.

Answer and Explanation:

To troubleshoot the problem, first issue the show running-config on all of 4 routers. Pay more attention to the outputs of routers R2 and R3

The output of the “show running-config” command of R2:


The output of the “show running-config” command of R3:


We knew that all areas in an Open Shortest Path First (OSPF) autonomous system must be physically connected to the backbone area (Area 0). In some cases, where this is not possible,we can use a virtual link to connect to the backbone through a non-backbone area. The area through which you configure the virtual link is known as a transit area. In this case, the area 11 will become the transit area. Therefore, routers R2 and R3 must be configured with the area area-id virtual-link neighbor-router-id command.

+ Configure virtual link on R2 (from the first output above, we learned that the OSPF process ID of R2 is 1):

R2#configure terminal
R2(config)#ipv6 router ospf 1
R2(config-rtr)#area 11 virtual-link

(Notice that we have to use neighbor router-id, not R2’s router-id

+ Configure virtual link on R3 (from the second output above, we learned that the OSPF process ID of R3 is 1 and we have to disable the wrong configuration of “area 54 virtual-link”):

R3#configure terminal
R3(config)#ipv6 router ospf 1
R3(config-rtr)#no area 54 virtual-link
R3(config-rtr)#area 11 virtual-link

We should check the configuration on R4:

R4#show running-config

You will see a wrongly configured virtual-link command. To get full mark we have to disable this command:

R4#configure terminal
R4(config)#ipv6 router ospf 1
R4(config-rtr)#no area 54 virtual-link

After finishing the configuration don’t forget to ping between R1 and R4 to make sure they work well!

Now all the configuration was done. But we still cannot ping the IPv6 loopback interface of R4 from R1 because the IPv6 loopback interface of R4 has not been advertised into OSPFv3. But we can check by using the command show ipv6 route on R1. If you can see the IPv6 loopback interface of R4 then you don’t need to do anything else.

But in real routers, we have to advertise the IPv6 loopback interfaces of R1 & R4 into OSPFv3 to make them appear in the routing tables with the following commands:

R4(config)#int loopback 0
R4(config-if)#ipv6 ospf 1 area 54

R1(config)#int loopback 0
R1(config-if)#ipv6 ospf 1 area 0

Again, the above commands should only be used when you don’t see the IPv6 loopback interface of R4 in the IPv6 routing table of R1 as the exam requirement.

The copying running-config startup-config command will not work but don’t worry, just skip it.

Notice: If you issue the command “show running-config” on R1, you will see these two lines:

passive-interface default
no passive-interface fa0/0 (fa0/0 is the interface connecting with R2)

These two lines make all the interfaces of R1 become passive interfaces except interface fa0/0. They are correctly configured so don’t try to disable them.

Other lab-sims on this site:

EIGRP Stub Sim


EIGRP OSPF Redistribution Sim

EIGRP Simlet
Policy Based Routing Sim

Comment pages
1 2 3 32
  1. Shabooyma
    January 22nd, 2019

    Hello friends,
    can someone share the update dumps of CCNP RS 300-101

  2. SW
    January 22nd, 2019

    Hi Guys, Hope you are fine… Can you please assist me in order to get CCNP ROUTE dumps.


    Thanks in advance for the attention & consideration.

  3. Admiral
    January 22nd, 2019

    “It is weird that we can’t ping the IPv6 loopback interface of R4 (with the ping or ping ipv6 command) but we can check by using the command show ipv6 route on R1”

    Just assign an ipv6 address to the fa0/0 interface of R1 and ping will pass correctly.

  4. Anonymous
    January 25th, 2019

    Guys in the exam they did not ask to ping they just say:

    Your task is complete when R4’s loopback address (FEC0:4:4) can be seen in the routing table of R1.

  5. boomboom
    January 26th, 2019

    just a show ip route on R1 shall do it.

  6. Hagler
    February 14th, 2019

    Did anyone tried to do this one GNS3?
    Because in reality, at GNS3, if you remove area 54 virtual-link it will not perform adjacency and R3 will not learn R4 loopback (FEC0:4:4).

    Any thoughts? ill still go with what digitaltut and everybody here experienced but would like to know if anyone saw it and explain what happened


  7. Andrew
    February 17th, 2019

    Same thing happened to me,
    unable to find R4 Loopback ip in R1 after removing area 54 command
    did u found any solution for this

  8. Anonymous
    February 20th, 2019

    Don’t over-complicate it guys…it’s pretty damn easy.

  9. gent
    February 20th, 2019

    im not see R4’S Loopback on r1 after doing this

  10. juls
    February 21st, 2019

    I have the same problem, using GNS3 is neccesary to keep virtual-link between R3 and R4, not just between R2 ans R3.
    I created the link between R2 and R3 and R1 was not able to learn route to R4. After several attempts, I re add again link between R4 and R3 and Ping is succesful.

  11. Anonymous
    February 24th, 2019

    Hi guys,

    quick question, see when it comes to configuration for these sims, how is it done in the actual exam? Do we configure right onto a CLI or do we insert commands into boxes like on these SIMS ?

  12. Anonymous
    February 24th, 2019

    Hi Guys,

    Can someone please explain to me why we need a virtual link on R2, when that has an interface already connected to Area 0? Even the explanation above mentions that we use a virtual link to connect to Area 0 when the device cannot physically connect to the backbone area…

    Also, to reply to my buddy @Anonymous above, I believe we will be using CLI rather than the text boxes on digitaltut.

  13. k3n3
    February 25th, 2019

    guys on all the sims, do we need to wri mem or save the config or not? for as long as it will work?

  14. Antares
    March 8th, 2019

    If you are looking for latest dumps just email me antaresccnp @ outlook . com.

    I have also latest Switch and T-SHOOT.

  15. meloo
    April 1st, 2019

    Pass today, 925
    Chinese dump valid
    Labs PBR, EIGRP OSPF redistribute, IPv6

  16. meloo
    April 1st, 2019

    Thanks digitaltut and all!
    email: philipsmeloo @gmail .com

  17. joanale
    April 21st, 2019

    you need to use virtual link to connect external areas R1 with R4.

  18. Dotcom
    June 3rd, 2019

    Guys can some please share sites where we can find latest dump. someone who is not selling the dumps please.

  19. jonny
    June 19th, 2019

    does anyone have lasted dump in JUNE?

  20. meloo
    June 20th, 2019

    you guys can reach me. Good luck!

  21. Jahangir
    June 20th, 2019

    I cant execute show commands in sim is there anybody else that are facing the same problem

  22. HeyupThere
    June 23rd, 2019

    @Jahangir Im running show run without problem on all four RT.

  23. benz
    July 6th, 2019

    R1#show ipv6 route
    IPv6 Routing Table – 6 entries
    Codes: C – Connected, L – Local, S – Static, R – RIP, B – BGP
    U – Per-user Static route
    I1 – ISIS L1, I2 – ISIS L2, IA – ISIS interarea, IS – ISIS summary
    O – OSPF intra, OI – OSPF inter, OE1 – OSPF ext 1, OE2 – OSPF ext 2
    ON1 – OSPF NSSA ext 1, ON2 – OSPF NSSA ext 2
    L FE80::/10 [0/0]
    via ::, Null0
    C FEC0::/28 [0/0]
    via ::, Loopback0
    L FEC0:1::1/128 [0/0]
    via ::, Loopback0
    OI FEC0:2::2/128 [110/10]
    via FE80::C202:11FF:FEE0:0, FastEthernet0/0
    OI FEC0:3::3/128 [110/74]
    via FE80::C202:11FF:FEE0:0, FastEthernet0/0
    L FF00::/8 [0/0]
    via ::, Null0

  24. suntzu
    July 23rd, 2019

    I’m now sure why this line is HERE

    [quote]You will see a wrongly configured virtual-link command. To get full mark we have to disable this command:

    R4#configure terminal
    R4(config)#ipv6 router ospf 1
    R4(config-rtr)#no area 54 virtual-link[/quote]

    I did not have this lab on my test but testing it in GNS3 with the exact same configs as listed, i tripled check the configs to make sure. I see that you will see router 4’s route in R1’s table no matter if you remove the wrong virtual links between R3 and R4 or if you leave them there.

    I just tested with them in and removed, same thing, seeing FEC0:4::4 no matter.
    Plus, the directions do not say anything about correcting “unneeded” configs.

  25. Azteca
    August 28th, 2019

    Hello friends,

    Would you send me the last dump 300-101? My exam will arrive soon and ask me if you can share it, please. Thank you

    extreme_z3r0 @ hotmail . com

  26. paheocon
    September 8th, 2019

    Dear all,
    In IPv6 OSPF Virtual Link Sim, I tried in GNS3 but the result after show ipv6 route on R1 didn’t include R4 Loopback.

    Do we need to include below command in real exam:

    R4(config)#int loopback 0
    R4(config-if)#ipv6 ospf 1 area 54

    R1(config)#int loopback 0
    R1(config-if)#ipv6 ospf 1 area 0


  27. Anon
    September 16th, 2019


    “Your task is complete when R4’s loopback address (FEC0:4:4) can be seen in the routing table of R1.”

    so yes, you need to include this!

  28. Ann
    September 17th, 2019

    Has anyone tried this on packet tracer? I can’t get a working image for GNS3.

  29. Reikidude
    September 17th, 2019

    Packet tracer not provide a lot of command needed for the ccnp

  30. Ann
    September 17th, 2019

    Thanks Reikidude. Yes, it doesn’t work for all. Can you please suggest how/where should I look for GNS3 images?

  31. ppk slb
    October 13th, 2019

    Guys, a friend of mine took Route today and passed; for some labs, copy run start/wr works, while some does not (involved config change). If it does not work, you marks won’t get deducted (as they meant the exam to be like that). ‘Pipe’ does not work. Thankfully ‘tabbing’ works. For some commands that does not work, you have to find another way to verify (sh run etc – Cisco did this to ensure you know how to verify thru configs instead of IOS command). There’s one command ‘sh ip eigrp topology’ does not work, but ‘sh ip eigrp 1 topology’ works. So please state the process id if it does not work. He said labs are fine, the objectives quite hard.

    Below is his comments;


    But please do not memorize dumps cause some questions they changed something – please ensure u understand it.

    If some commands does not work and you were not meant to use it, the error message will say ‘Command not implemented etc…’ when you executed the IOS command.
    There’s always another way to verify/troubleshoot it (sh run etc…)

    13th Oct; Passed with 839/1000


    EIGRP Evaluation Sim – comments below;
    -command ‘sh ip route’ on R6 does not work; i can only do ‘sh run’
    -why do i need to use ‘sh ip route’? Because there’s 2 loopback configured at R6, i need to know
    which one should i choose
    -so i guess Cisco purposely disable it to make my life hard; they want us to verify routing via configs
    -from ‘sh run’ at R6, i can see that is configured, but it was not advertised out because there’s
    ‘distribute-list 1 out’ being configured, where the ACL denied loopback IP
    -another simpler way to verify is that ‘’ loopback is not shown in R1 routing table (sh ip route); thus we can say that loopback ip that we should use is
    -another thing to take note is that ‘show ip eigrp topology’ command does not work in R1 (not sure on other router, i haven’t tested it out) – per suggested on Digitaltut, we should use the EIGRP process ID. Then it works like charms. I’ve executed ‘sh ip eigrp 1 topology’ and it works. Luckiliy i read this part from Digitaltut. However, if this happens and you don’t have any idea on this, i guess ‘tab’ or ‘tabbing’ will give you an idea (tabbing works in Exam labs)

    OSPF Sim – comments below;
    -everything the same except the IP. no surprises here. easy.
    -tabbing works, and copy running-config startup-config works. I did ‘wr’ command too and it works.

    IPv6 OSPF Virtual Link Sim – comments below;
    -copy run start/copy running-config startup-config/wr does not work – so just ignore it (you marks won’t get deducted)
    -everything is the same
    -in this scenario, i can see the loopback ip from R1 after added and remove virtual links, so i don’t have to make any changes on the
    loopback ip (that has to be in area interfaces)

    October 15th, 2019

    who needs updated dump and materials for ROUTE can reach me at: cisco4career @ gmail . com
    Good luck guys!

  33. azkhan
    November 12th, 2019

    I have passed CCNP Route yesterday 11/11/2019.
    Labs were OSPF Virtual-link & OSPF sim (stub )

    4 to 5 Drag & drop
    others questions related to

  34. anonymous
    November 30th, 2019

    @azkhan, The OSPF Virtual-link Lab is correct within the 9tut above Lab?

  35. Liaqat
    December 8th, 2019

    One of the questions in my exam was virtual-link area 11, but I done and pass the exam. One thing was confusing that after configuration running copy running-configuration start-configuration didn’t work. Did someone experienced this problem?

  36. Stas
    December 15th, 2019

    “show running-config” doesnt work at this sim on this site.

  37. Anonymous
    December 18th, 2019

    in my lab this only works when i enable the loopbacks for ospfv3 like paheocon mentioned before:

    R4(config)#int loopback 0
    R4(config-if)#ipv6 ospf 1 area 54

    R1(config)#int loopback 0
    R1(config-if)#ipv6 ospf 1 area 0

    Without those commands i neither see R4 loopback on R1 nor i can ping R4 from R1.

  38. cyberknock
    December 19th, 2019

    Passed today with 843.

    Labs: OSPFv3, EIGRP Eval, OSPF Sim

    @OPSFv3 Lab:
    The loobbacks are of course on any router enabled for ipv6 eigrp … so maybe Digitaltut could correct the configuration here?

    Thanks a lot guys and many luck to you, i am heading for tshoot now

  39. Anonymous
    December 27th, 2019

    This is the current configuration in R1:
    interface Loopback0
    no ip address
    ipv6 address FEC0:1::1/64
    ipv6 ospf 1 area 11

    is this a typo, and instead of area 11, it is area 0?


  40. digitaltut
    December 28th, 2019

    @Anonymous: If this config is in R1 then it is a mistake and it should be fixed as you said. Where did you see this config?

  41. ficksilopostly
    January 2nd, 2020

    Hi guys

    i made this lab in GNS3, about the problem with the loopbacks in r1 and r4, i did this and it works

    R1#conf term
    Enter configuration commands, one per line. End with CNTL/Z.
    R1(config)#int loopback 0
    R1(config-if)#ipv6 ospf 1 area 0
    R1#clear ipv6 ospf 1 process
    Reset OSPF process? [no]: yes
    *Mar 1 00:47:54.291: %OSPFv3-5-ADJCHG: Process 1, Nbr on FastEthernet0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
    *Mar 1 00:48:01.359: %OSPFv3-5-ADJCHG: Process 1, Nbr on FastEthernet0/0 from LOADING to FULL, Loading Done

    R1#sh ipv6 ospf neighbor

    Neighbor ID Pri State Dead Time Interface ID Interface 1 FULL/DR 00:00:38 4 FastEthernet0/0

    R1#ping fec0:4::4

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to FEC0:4::4, timeout is 2 seconds:
    Success rate is 100 percent (5/5), round-trip min/avg/max = 48/88/176 ms

    best regards

  42. ZanryL
    January 7th, 2020

    Will there be a new set of test after February 23, 2020? It seems there is currently a major update with regards to certifications.

  43. Yep
    January 15th, 2020

    Had this one today Lab is valid!

  44. failed ccnp route
    January 19th, 2020

    i have a premium account, maybe you have to correct you lab with the loopback config to check, with the config here i can not ping from R1 to R4.
    thanks in advance

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