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IPv6 OSPF Virtual Link Sim

May 8th, 2014 in Lab Sim, LabSim Go to comments

Question

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.

OSPFv3_IPv6_VirtualLink

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:

OSPFIPv6v3VirtualLink_show_run_R2

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

OSPFIPv6v3VirtualLink_show_run_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>enable
R2#configure terminal
R2(config)#ipv6 router ospf 1
R2(config-rtr)#area 11 virtual-link 3.3.3.3

(Notice that we have to use neighbor router-id 3.3.3.3, not R2’s router-id 2.2.2.2)

+ 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 4.4.4.4”):

R3>enable
R3#configure terminal
R3(config)#ipv6 router ospf 1
R3(config-rtr)#no area 54 virtual-link 4.4.4.4
R3(config-rtr)#area 11 virtual-link 2.2.2.2

We should check the configuration on R4:

R4>enable
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 3.3.3.3

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. 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

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

OSPF Sim

EIGRP OSPF Redistribution Sim

EIGRP Simlet
Policy Based Routing Sim

Comments
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  1. @studdingalot
    September 13th, 2017

    All sims are similar to what you see on this website , but most of the multiple choice are different …loads of DMVPN , TCP/UDP , IPV6 and simlets

  2. mantuika
    September 29th, 2017

    Cool guy, the area between AREA-0 & AREA-54 is AREA-11. That is the transit area, not 54.

  3. Moreseas
    October 3rd, 2017

    Re: Cool-Guy
    Think of it this way; Area 11 is just fine because it has at least one router in the backbone area 0, the virtual-link command is technically merging area 54 with area 11 so as to satisfy the condition of having at least one interface in the backbone area. That is a good way to look at it.
    Let me know if this helps you

  4. Chikku
    October 29th, 2017

    Anyone who took the exam recently can confirm which are the SIMs in the exam?????
    I’m gonna take it early next week.
    Please respond asap.

  5. Dgo
    October 29th, 2017

    Thank you FRANKIE

  6. Dgo
    October 29th, 2017

    Just added all of the Labs into one big GNS3.. hit me up if you are interested>

    https://plus.google.com/u/0/117541681808420450293/posts/A9s8EFryh7c

  7. nowlad
    October 30th, 2017

    @ all, please help:

    When I do on R3: no area 54 virtual-link 4.4.4.4 and on R4 no area 54 virtual-link 3.3.3.3

    Than I cannot ping FEC0:4::4 and I cannot see it with show ipv6 route ..

    Why? Is the GNS3 Lab wrong?? Please help

  8. hacker
    November 2nd, 2017

    about the show ip route on IPv6 OSPF virtual link. why FEC0:4::4 does not appear on R1. I follow all of the steps that written here on this site. PLEASE HELP..

    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::C202:14FF:FEE4:0, FastEthernet0/0
    OI FEC0:3::3/128 [110/74]
    via FE80::C202:14FF:FEE4:0, FastEthernet0/0
    L FF00::/8 [0/0]
    via ::, Null0

    R4#show ipv6 route
    IPv6 Routing Table – 7 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
    OI FEC0:1::1/128 [110/84]
    via FE80::C203:14FF:FEE4:0, FastEthernet0/0
    OI FEC0:2::2/128 [110/74]
    via FE80::C203:14FF:FEE4:0, FastEthernet0/0
    OI FEC0:3::3/128 [110/10]
    via FE80::C203:14FF:FEE4:0, FastEthernet0/0
    L FEC0:4::4/128 [0/0]
    via ::, Loopback0
    L FF00::/8 [0/0]
    via ::, Null0

  9. Dim
    November 16th, 2017

    @hacker: Look the message from @frankie. Check Loopback0 on R1 and on R4 – they aren’t participate in an OSPF process.
    So add ip ospf 1 area 0 for L0 on R1 and ip ospf 1 area 54 for L0 on R4.

  10. Dim
    November 16th, 2017

    @hacker: Sorry, a little mistake in commands:
    ipv6 ospf 1 area 0 – on R1
    ipv6 ospf 1 area 54 – on R4

    show ipv6 ospf int – to check what interfaces are participating in an OSPF on this router for IPv6.

  11. LightStealer
    December 3rd, 2017

    @frankie @Dim. Do we need to change the area assignments on these loopbacks? As the instructions says, we are not allowed to change the area assignments.
    I changed the area assignments on the loopbacks and I can ping already. Is this true as well on the real exam? Or this lab has the wrong configuration?

  12. PTT
    December 4th, 2017

    @nowlad: Than I cannot ping FEC0:4::4 and I cannot see it with show ipv6 route ..

    -> you should type these command in R1’s int l0 and R4’s int l0
    interface Loopback0
    ..
    ipv6 ospf 1 area 54

    and
    interface Loopback0
    ..
    ipv6 ospf 1 area 54

  13. LightStealer
    December 6th, 2017

    @frankie @Dim. Do we need to change the area assignments on these loopbacks? As the instructions says, we are not allowed to change the area assignments.
    I changed the area assignments on the loopbacks and I can ping already. Is this true as well on the real exam? Or this lab has the wrong configuration?

  14. Anonymous
    December 15th, 2017

    hi
    I still dont understand why we need to lo0 of R1 to be in area 0 in order to ping lo0 of R4

  15. Joe
    December 17th, 2017

    I have downloaded the lab from here , all the routers are empty from configuration. why?

  16. dumpspro
    January 26th, 2018

    latest dumps ccie 400-101

    dumpspro.com/ccie-dump

  17. ccnp83
    March 3rd, 2018

    how can i downgrade my gns3,i cant seem to open any of the GNS files shared due to version incompatibility,any idea please.I cant find old GNS3 versions anywhere.

  18. Jola
    March 6th, 2018

    Hi
    any one have real exam GNS Lab Sim for all labs?

  19. Anonymous
    March 22nd, 2018

    can you provide me the IOS Image which can open this virtual link ospf lab in gns3. PLSSS

  20. Grash
    April 3rd, 2018

    I don’t know why R1 receive R2 and R3 loopback ip routes without configuring them in ospf process and it is needed to include R4 and/or R3 loopback interface in ospf process in order to receive in R3/R4. Any idea?

    Also, why it is not receiving R1 routes of Fastethernet of R4 or Serial of R3?

  21. Elv
    April 16th, 2018

    If you were not able to ping R1 loopback address then it means the loopback interface was not added to area 0.

  22. Jpar
    April 18th, 2018

    Could someone please help me with the CCNP route latest dumps.
    email :: jigar231@gmaildotcom

  23. NealCont
    May 14th, 2018

    ¿¿How do you ping between R1 and R4??

  24. mujib
    June 9th, 2018

    How to add ipv6 LOOPBACK address FECO:1::1 ON Cisco router
    can someone show me and email me on syedmr4 at yahoo.co.uk

  25. Anonymous
    June 19th, 2018

    hello mujib,

    on the very interface

    R1(config)#int f0/0
    R1(0nfig-if)#ipv6 ospf 1 area 0

    it just a example for you

  26. Anonymous
    July 20th, 2018

    had a weird experience in the exam with this lab: as soon as I took out the unneeded virtual-link between R4-R3, the neighbor adjacency went down yet the loopback from R4 would show up in R1. Even after the correct virtual-link came online, there were no Neighbor FULL status messages, yet if I put the unneeded virtual-link on there, I would get the syslog for Neighbor Full.

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