IPv6 OSPF Virtual Link Sim
Question
Acme is a small export company that has an existing enterprise network that is running IPv6 OSPFv3. Currently OSPF is configured on all routers. However, R4′s loopback address (FEC0:4:4) cannot be seen in R1′s IPv6 routing table. You are tasked with identifying the cause of this fault and implementing the needed corrective actions that uses OSPF features and does no change the current area assignments. You will know that you have corrected the fault 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>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:
Can any one tell me dat do dey ask to assign the ipv6 addresses in this sim !!!!!! or jst confgure the ospf operability!!!!!
@ABC:
In the real exam you have only to configure virtual link on R3 (to 2.2.2.2), the virtual link on R2 (to 3.3.3.3) and delete all other virtual links on the routers (with no …) …
… Because … “…if You will see a wrongly configured virtual-link command, you have to disable this command to get full mark”
That’s it!
imho
passed today with 953 / 1000
– same SIM with area changed , got 100 %
Thank DigitalTut
@Ghost from Germany
Can you please explain why we need to include int loopback 0 in the ospf Process on R1?
I tried without but not able to ping though i see the loopback in the routing table of R1. What is the reason behind it?
Thanks
hi friends please send me latest dumps of ccnp …….
and send me vc please
Hi All,
I took the exam last week with max score.
Not EIGRP Simlet, not OSPF Hotspot.
The other 5 configuration labs are present in the exam and valid.
Don’t worry if you can’t do a ‘copy run start’ in the real exam (type it and good).
Ip addresses, names, areas and processes can change!
Don’t type blind!!! Know the concept and the commands!!!
And you are on the safe side.
Thanks digitaltut, Boyi n Peter (All question from these only).
To make this work on GNS3, kindly add the configuration below:
On R1:
R1#conf t
R1(config)#int lo0
R1(config-if)#ipv6 enable
R1(config-if)#ipv6 ospf 1 area 0
On R2:
R2#conf t
R2(config)#int lo0
R2(config-if)#ipv6 enable
R2(config-if)#ipv6 ospf 1 area 0
On R3
R3#conf t
R3(config)#int lo0
R3(config-if)#ipv6 enable
R3(config-if)#ipv6 ospf 1 area 54
On R4:
R4#conf t
R4(config)#int lo0
R4(config-if)#ipv6 enable
R4(config-if)#ipv6 ospf 1 area 54
Happy simulation everyone! cheers :)
@Asthran16:
You are right! But in the real exam it’s not necessary!
Imho it’s smarter to edit the *.cfg befor you start this GNS3 lab?!?
All can find it in my post of March 26th, 2013 on previous page.
Good luck to all.
how can i ping between R1 n R2? i mean which ip address i should use to ping?
ans me soon
Does the TAB or ” ? ” work in the exam ?
thanks guys
I Downloaded GNS Sim from here.
When I remove area 54 virtual-link 4.4.4.4 on R4, it doesn’t display ipv6 route table on R1.
But when I leave it, I can see the R4′s loopback address on R1.
Is the sim outdated? What is the correct procedure?
@xrep
I have the same issue. The only way I can make the ping ipv6 works is to add loop0 (R4) and loop0 R1 to area 54 and 0 respectively. Could be bug on the IOS, I should test that with a different version and router model.
why are we using this command no area 54 virtual-link 4.4.4.4, if we dont put this command how will area 54 connected with the area 0
Guys, passed the test on 16/04/13. The information is still valid. Regarding this lab, dont worry. The lab already has ospf configuration in loopback interfaces. Actually, ping ipv6 is not implemented in the simulator. The loopback 0 of R4 in R1 routing table is enough.
type : PDF
Price :Free : )
update date 15 MAR
http://www.2shared.com/document/YWw6jX-r/642-902qa358.html
and dont Forg8 5 labs
1-OSPF EIGRP Redistribute Lab
2-OSPF Sim
3-IPv6 OSPF Virtual Link Sim
4-EIGRP Simleter
5-Policy Based Routing Sim
for Lab
what Crovax said. Took this test yesterday and it’s true. ping is not implemented. The only requirement of the lab is for FEC4::4 to show up in the routing table of R1. That’s it.
This lab as it’s written here is good to go.
Hello Guys,@Anonymous :you are right I Didn’t Saw FEC0:4::4/128 on R1 Routing table when i removed the command area 54 virtual-link 4.4.4.4 but when I Let is as It Everything Goes well
@Islam
No, you do need to remove area 54…
The virtual link on R4 and R3 needs to be removed before you add the virtual link between R2 and R3.
Part of the lab is also to remove the wrong configuration. Read the instructions.
about ipv6
interface Loopback0
no ip address
ipv6 address FEC0:4::4/28
ipv6 ospf 1 area 54
if you do not see (OI FEC0:4::4/128 [110/84]
) in you sh ipv6 route commant on R1 please add ipv6 ospf 1 area 54 on R4 under loopback0
it should look like as i did above
my previous post is wrong. i corrected in this way at router 4 i also add under ospf
area 54 virtual-link 3.3.3.3 command. i found everything works even i can ping
ipv6 router ospf 1
router-id 4.4.4.4
log-adjacency-changes
area 54 virtual-link 3.3.3.3