Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > Neighbor States > Full > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > OSPF Database Exchange Process > Confirming Completion > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > Hello Interval > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > Dead Interval > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > Handling Topology Changes > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > LSAs > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > LSDBs > Maintaining The Full Neighbor State
Root: WRM Database > Information Technology > Certifications > CCNA > Routing Protocols > OSPF > The SPF Algorithm > Maintaining The Full Neighbor State



Maintaining The Full Neighbor State


OSPF uses the Full neighbor state to mean that the database exchange process has been completed. Neighbors in a Full state still do some maintenance work. They keep sending Hellos every Hello Interval. The absence of Hellos for a time equal to the Dead Interval means that the connection to the neighbor has failed. Also, if any topology changes occur, the neighbors send new copies of the changed LSAs to each neighbor so that the neighbor can change its LSDB. For example if a subnet fails, a router updates the LSA for that subnet to reflect its state as being down. That router then sends the LSA to its neighbors, and they in turn send it to their neighbors, until all the routers again have an identical copy of the LSDB. Each router can then also use SPF to recalculate any routes affected by the failed subnet.







References

Odom, Wendell (2008) CCNA ICND2 Official Exam Certification Guide, Second Edition. Indianapolis: Cisco Press.