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Route This Way: OSPF

 
Something I very recently learned is that routing protocols are learned on Control Planes.

Also, welcome to possibly the last post of 2019. I need a break too! 

There's plenty more coming in 2020. Meanwhile, visit and follow the new LinkedIn Company Page, if you please.





Many of these protocols will have very similar commands - network [network] wildcard [wildcard] - and OSPF has areas.



An area limits the scope of route information distribution. - mainly, less routes to propagate by summarizaton.

Look back at the image; The middle router, 4(2), is what we call a backbone area, that has interfaces in both area 1 (Router 4(1)) and area 2 (Router4).

Area 3 up there is a non-entity.

This is with the left side, area 1, having fully converged with the middle router.

Here are the outputs for show ip ospf for each router: Backbone;


All three areas are acknowledged, even our interfaceless area 3 up there.

Area 1 (left):

Interfaces in the area include its serial link and the Copper ST cable to the LAN.

Area 2 (right):

You may have noticed "Routing Process "ospf 1" and have been confused - processes and areas aren't the same thing. Processes are more for us to know what group of routers we may be working with.
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