Straight to the point... Let us learn how OSPF creates and maintains the same LSDB across all nodes in one area.
For that we need to look at all the route types. First let us see from OSPFv2 perspective.
These are some of the nice resources I could come across:
https://packetpushers.net/ospf-graphs-lsas-and-the-lsdb/
The approach is here is to read through the articles, ask self queries and try to make the understanding clear here.
The steps are pretty simple:
* From all the LSAs received a graph is created ( LSDB graph)
* The graph becomes input to the SPF algorithm which creates the best path OSPF routes.
Let us look at the various LSA types in OSPF and see how LSDB is formed. We will look at only the basic necessary fields to populate the LSDB.
Type 1: Router LSA.
It contains Link ID - which is the unique Router ID and can be used to identify the Router.
The Router LSA will also contain the links attached to the Router. It will have all the prefixes which the router has configured OSPF ( including the active and passive interfaces).
Each links will be processed separately in SPF calculations
TO CONTINUE:
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