OSPF Phases

• Hello

• • Discover, establish, maintain relationships between adjacent routers
  • Elect a designated router (DR) and backup designated router (BDR), if required
  • Periodic keepalive

• Database Discovery

• • Initial synchronization of databases between two newly-adjacent routers (typically between the DR and the new router)

• Link State Updates (aka Flooding)

• • When the state of a router’s link changes (e.g., up to down), the router sends a link-state update out of all of its interfaces that are running OSPF