11-07-2019 05:20 AM
Studying for my ROUTE exam and had a practice question yesterday that I am kind of stuck on. Here is a picture of what the topology was like....
Every router ID was it's router number 4 times (R1 = 1.1.1.1, R2 = 2.2.2.2, R3 = 3.3.3.3). The issue is the loopback of R3 was not showing up in the routing table of R1. Obviously it is because R3 needs a virtual link to connect it to Area 0. So I did a show run on R3 and there was already a virtual link configured and it was conifigured as "area 10 virtual link 2.2.2.2".
Well I know that is wrong because the area you specify needs to be the transit area. So I then issued the following command.......
R3:
conf t router ospf 1 area 1 virtual link 2.2.2.2
R2:
conf t
router ospf 1
area 1 virtual link 3.3.3.3
When I did this, a "show ip ospf virtual links" told me that the virtual link was "down". The other incorrect virtual link was still in the config, so I did negated it was a "no" and got rid of it on both routers. After doing this, it made no difference, the new virtual link was still down and I could not get the loopback of R3 to show up in the routing table of R1.
Does anyone have any idea how to troubleshoot a down virutal link? I had never run into this before so was very confused. I also just set this up in GNS3 and had no issues getting it to work.
11-08-2019 07:22 AM - edited 11-08-2019 07:24 AM
Hello
you’ll need to check if the correct abrs are being defined and their relating rids are reachable through the transit area they are going to connect through.
Also one of the two rtrs in the VL needs to be in the BB area 0 and also the transit area for the VL to establish
Other factors could be ACLs or FW ruling negating access.
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