10-29-2021 09:29 AM - edited 10-29-2021 09:31 AM
I made this network below in packet tracer.
This is my packet tracer file.
Even after going over this issue 13 times I'm not able to fix it . The problem is that I'm not able to see "OSPF Learned Routes" in the routing table of each of the four Area Border Routers , even when OSPF Hello packets are moving . I even went on the simulation mode and checked the OSPF Hello packets and found nothing wrong.
I created 4 ABR's and each of them is connected to 3 areas . When I enabled OSPF on all the four routers the OSPF is working fine . I'm able to see the neighborship and I saw that hello timers and dead timers are updating , I absolutely made sure that all commands I entered were correct ; I even made the same topology in GNS3 to see if the packet tracer had some sort of bug well it still didn't work out .
I'll be really happy and thankful if someone helps me solve this problem.
Solved! Go to Solution.
10-29-2021 10:58 AM
Hello,
area 2 has no link to the backbone. Create virtual links as below:
R1
router ospf 11
router-id 1.1.1.1
log-adjacency-changes
area 4 virtual-link 3.3.3.3
R2
router ospf 22
router-id 2.2.2.2
log-adjacency-changes
area 3 virtual-link 4.4.4.4
R3
router ospf 33
router-id 3.3.3.3
log-adjacency-changes
area 4 virtual-link 1.1.1.1
R4
router ospf 44
router-id 4.4.4.4
log-adjacency-changes
area 3 virtual-link 2.2.2.2
Attached the revised file (saved in PT version 8)...
10-29-2021 10:58 AM
Hello,
area 2 has no link to the backbone. Create virtual links as below:
R1
router ospf 11
router-id 1.1.1.1
log-adjacency-changes
area 4 virtual-link 3.3.3.3
R2
router ospf 22
router-id 2.2.2.2
log-adjacency-changes
area 3 virtual-link 4.4.4.4
R3
router ospf 33
router-id 3.3.3.3
log-adjacency-changes
area 4 virtual-link 1.1.1.1
R4
router ospf 44
router-id 4.4.4.4
log-adjacency-changes
area 3 virtual-link 2.2.2.2
Attached the revised file (saved in PT version 8)...
10-29-2021 11:03 AM
Hello
TBH you wouldnt have a network like that, It makes no sence and in a active production network if you had to create multiple VLs then you have ran into a bad ospf design.
10-29-2021 12:56 PM
Agreed with @paul driver here, why not get cable and connect, rather virtual link - that only used were really required, that is not the standard use case.
10-29-2021 01:28 PM
@balaji.bandi Just out of curiosity:
--> Agreed with @paul driver here, why not get cable and connect, rather virtual link - that only used were really required, that is not the standard use case.
The routers are fully meshed physically already, what additional cable would you use to solve the problem of area 2 not being connected to the backbone ?
10-29-2021 03:32 PM
Maybe i have not made clear if the devices mesh and why not that interface part of area 0, - rather virtual link. ( i am more concerned area 5 links - why area 5 required here ?) - since i don't have PT and not sure what is configured, this based on the pictorial information my comment.
have anyone ever used in the real-world so many virtual links to solve the issue? ( agreed this is a lab, can imagine many use cases as like).
this is just my thought.
10-30-2021 03:07 AM - edited 10-30-2021 03:19 AM
Hello
The whole idea of VL is to make a connection to the backbone and as these rtrs are full meshed anyway, The most simplistic solution would to change area 5 to area 0 then area 2 isnt isolated and no VLs to contend with.
10-30-2021 08:48 AM
"I created 4 ABR's and each of them is connected to 3 areas."
No you have not. Only your two left most routers are ABRs. ABRs need a connection to area zero.
Although your two right most routers have connections to multiple (non-zero) areas, and they will route between those areas if a packet transits them, they will not share area (route) information between those connected areas.
You want to try changing your area 5 links to area 0 and your area 0 links to area 5. Then see what your route tables look like.
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