Everything you have seen about OSPF so far shows that it is a highly structured protocol. Knowing the importance of reliable and accurate database synchronization, it is no surprise that a rather complex state machine, called the neighbor state machine, manages the OSPF synchronization procedure. In a nutshell, the neighbor state machine drives the following steps in the synchronization process:
When two neighbors decide to become adjacent, one of the neighbors becomes the master and the other the slave. The master controls the rest of the synchronization process, called database exchange.
Each neighbor describes all of the LSAs in its database to the other.
If a router finds, during the description ...