My prediction about covering network types was wrong.  I’m going to puke out some information about neighbor states for now.  As is always the case, corrections are welcome.

Down : No hellos have been received from this router.

Attempt : This state only applies to manually-configured neighbors on an NBMA network.  In this state, a router has sent unicast hellos to the neighbor but has not received any back from it.

Init : The router has received hellos, but none of the hellos have the router’s RID included as a known neighbor.

2way : The router has received hellos with its RID included.  This means the other router has received the hellos from this router, so they now have 2-way communication going.  The DR and BRD is elected at the end of this stage.

ExStart: When a router grows up and starts to have feelings for other routers, it enters the ExStart state to have further relations with a neighbor.  This is where the master/slave relationship and the initial sequence numbers are established.

Exchange : Once we know who wears the pants in this relationship, the master sends over a DBD with it’s LSAs listed.  In response, the slave does the same so that both routers have all the LSA headers they both know.

Loading : This is where the LSRs and LSUs flow.  If a router need the full LSA from the neighbor, it sends an LSR, and the neighbor should send an LSU in response.

Full : After the LSR/LSU exchange, the routers should both be in sync, so they each send an LSAck to the other to confirm.

As a bonus, here’s a nifty little animation showing neighbor states.