OSPF
- It is works on Dijkstra Algorithm
- It is purely a classless protocol
- It supports only VLSM
- It is a 2-layer hierarchy
- Minimizing the routing updates traffic
- With in the Area only all the information will send to all routers in that area (LSA)
- The ABR will send Auto summary information to the backbone area ( So burden will reduced on the main system)
- The Multi-cast address are
- 224.0.0.5 - All other routers will communicate through this Multicast address.
- 224.0.0.6 - All routers with DR router will communicate through this.
- NOTE: DR and BDR will Understand both packets from 224.0.0.5/6
- Its AD value is 110
- Its protocol number is 89
- Metric is calculated by using “ BANDWIDTH”
- Cost of path = Reference Bandwidth/My outgoing link BW
- Note: Reference BW in OSPF is 100 Mbps ( We can also change the Reference BW)
- EX: Serial – 1.54 Mbps = 64 cost, Fast Ethernet - 100Mbps = cost 1, Ethernet – 10Mbps = cost 10
