Before we begin to start talking about LSA flooding and how it uses LSUs to create the OSPF routing table, let's elaborate on this term.
There is not just one type of LSA either. Let's have a look at the following table:
By no means are these the only LSAs that exist. There are 11 LSAs, but for the CCNA, you must know about the ones that I highlighted, do not dismiss the rest.
LSA updates are sent via multicast addresses. Depending on the type of network topology you have, that multicast address is used.
For the point-to-point networks, the multicast address is 224.0.0.5. In a broadcast environment, 224.0.0.6 is used. But as we get further into OSPF and start discussing DR/BDR routers in a broadcast environment, the DR uses 224.0.0.5 and the BDR uses 224.0.0.6. In any case, remember that these two multicast addresses are used within...
