Configuring OSPF

Process of OSPF:

• Hello Packets are sent via Multicast to the neighbours.
• Directly connected Networks are put in a Link State Packet.
• The area gets flooded with this Packets.
• According to this the router knows what the network looks like.
• A topology database is built.
• Dijkstra Algorithm - Shortest Path Tree is created

If something in the network changes, the whole process starts again.

Exercise 8.2.2.7:

 

 To configure OSPF you need to configure a Router ID. There are three ways to get the router ID. 

1. Do nothing - highest IP address of the interface
2. loop-back interface -  IP address is set as router ID
3. directly set the router ID 

In this exercise all networks are in one area (area 1).
The wildcard mask is the inverted networkmask.

Afterwards you need to configure the passive interfaces (if there are only switches and end devices connected - OSPF packets will not be sent to this interfaces).