MicroNugget: Cisco OSPF Areas & LSA Types Explained | CBT Nuggets

Description :

In this video, CBT Nuggets trainer Jeremy Cioara explains Open Shortest Path First (OSPF) areas and Link State Advertisement (LSA) types. This is a blisteringly fast introduction to OSPF Areas and LSA types, crucial and complicated topics if you're dealing with OSPF configurations. If you're dealing with OSPF configurations, you're dealing with Areas and LSAs. When you begin with OSPF configurations, you must create Area 0. Some businesses never grow beyond this so-called backbone area. But as the business begins to grow and you begin adding more routers, your routing table can get pretty unruly. If there are too many routes, too many changes with networks going up and down, or processor cycles getting wasted, it’s important to break into multiple areas. In Link State Protocol, all routers in the area must have the same link-state database. The only way to hide routes or do route summarization is to break into multiple areas. Different areas include Stubby, Totally Stubby and Not-So-Stubby Areas. Yes, that's actually what they're called. Stub area is where you have an area that’s limited in what information can receive. Cisco allows for totally stubby areas which makes traffic highly efficient. A not-so-stubby area camouflages external routes for the sake of expediency. LSAs interact with the traffic and only some areas permit different LSAs. See which with Jeremy's explanation. 0:15: Backbone area, explained 0:55: Standard areas and stub areas 1:40: Cisco's totally stubby areas 2:15: Not-so-stubby areas 3:10: LSAs, Type 1 through 5 4:30: Which areas allow LSAs, and which