Open Shortest Path First (OSPF)

- An interior router protocol used in larger networks.

- A routers that sees a change to its routing table or that detect a change in the network immediately sends a multicast update to all other router in the network.

- OSPF vs. RIP

1. OSPF sends only the part of the routing table that has changed in its transmission. RIP sends the full routing tables each time.
2. OSPF sends a multicast only when its information has changed. RIP sends thee routing table every 30 seconds.

- If more than one OSPF are, one area must be area 0.0.0.0(the backbone area).

- All areas must be adjacent to the backbone area. If they are not, virtual link must be configure to the backbone area.

Routing Information Protocol (RIP)

- Used to manage router information in a self-contained network (LAN).


- Gateway host sends its routing table to the closest router each 30 seconds.


- Then send the contents of its routing tables to neighboring routers.


- Best for small networks, because the transmission of the full routing table each 30 seconds can load on the network.


- RIP tables are limited to 15 hops. 


- OSPF(Open Shortest Path First) is a better alternative for larger network.


- Two versions of RIP. 
1. RIPv1 -> uses a UDP(User Datagram Protocol) broadcast over port 520 to send updates to routing tables.
2. RIPv2 -> uses multicast to send routing table updates.


Tutorial:
1.Cisco How To Configure RIPv1
2.Cisco How To Configure RIPv2