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
Exercise 8.2.2.7:
To configure OSPF you need to configure a Router ID. There are three ways to get the router ID.
- Do nothing - highest IP address of the interface
- loop-back interface - IP address is set as router ID
- directly set the router ID
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).