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OSPF issue

Hi

Is it possible to create neighborship/communication between two non backbone area without the help of backbone area. If yes please share the method to do

2 REPLIES
VIP Super Bronze

Re: OSPF issue

Hello Sandeep,

In order for 2 routers to form an adjacency with each other, they have to be in the same area.

For example:

If you have router-1 and router-2 (below) and there is a link between these 2 routers, in order for them to become neighbors, the 2 interfaces must be in the same area.

router-1-------------area0---------------Router-2

Or

router-1-------------area1---------------Router-2

http://72.163.4.161/en/US/tech/tk365/technologies_configuration_example09186a0080094058.shtml

HTH

Reza

Re: OSPF issue

Dear Sandeep,

Two diferrent non-backbone areas are necessary to connect with Area 0 for the communication. Neihgbor relationship can be happen within the same area.

Virtual-Link is the solution to communicate non-backbone areas:

For example:

R1 >> Area 0  R2 >>  Area 1  R3 >>  Area 2  R4

By default Area2 cannot communicate with Area 1 or Area 0.

If we create Virtual-link between R2 and R3. Then Area 2 can communite with Area 1 and Area 0. R3 become an ABR and generates Inter-Area routes to Area 1.

Regards,

Anser

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