Neighbor States

Neighbor States
There are a total of eight states for OSPF neighbors:
Down
No Hello packets have been received from the neighbor.
Attempt
Neighbors must be configured manually for this state. It applies only to NBMA network
connections and indicates that no recent information has been received from the neighbor.
(Note: This state is not represented in Figure 5.1.)
Init
A Hello packet has been received from another router, but the local router has not seen itself
in the other router’s Hello packet. Bidirectional communication has not yet been established.
2Way
Hello packets have been received that include their own router ID in the Neighbor field.
Bidirectional communication has been established.
ExStart
Master/slave relationship is established in order to form an adjacency by exchanging
Database Description (DD) packets. (The router with the highest router ID becomes the master.)