OSPF: Open Shortest path first.
> Link state protocol
> Unlimited routers
> Open standard ( Mostly used IGP )
> Multicast : 22.214.171.124 and 126.96.36.199
> SPF algorithm - Dijkstra
> Administrative value : 110
> IP protocol : 89
Hello - 10 secs
Dead time - 40 secs
Types of Table :
> Neighbor table - Directly connected neighbors
> Database table - List of all the networks
> Routing table - Best paths
> OSPF has a concept of Areas.
> To stop Flooding of OSPF Packets.
> OSPF network should have Area 0.
> All the areas should connect to Area 0.
> Area 0 is also known as Backbone area.
> Router participates in multi-area is known as ABR.
> ABR Stands for Area Border Router.
ARea 1 ------- Area 0------- ARea 2
Types of packets
1. Hello - To discover the neighbors..
2. DBD - Database description
3. LSR - Link state request
4. LSU - Link state update
5. LsAck - Link state acknowledgment