OSPF & NBMA

• DR Election
• Requires manual neighbor establishment (neighbor command)
• In partial mesh ensure HUB is DR (priority command)
• Need to map spokes to hub, otherwise the spokes will not be able to communicate with each other.
• Neighbor will not show up when the neighbor is out a frame interface that is configured with priority 0
• A spoke should never be a DR or BDR in a true hub and spoke network. Make sure you always set the spoke's OSPF priority to 0.
• Neighbor statement is NOT required on routers that have IP OSPF PRIORITY 0 Don't configure network type broadcast or non-broadcast
• The default is non-broadcast on physical interfaces and multipoint subinterfaces.
• All interfaces point-to-multipoint. Note: Creates /32 host routes for the end points but doesn't need frame-relay mappings between the spokes.
• Point-to-multipoint on R1 and point-to-point on R2 and R3. The hello/dead timers need to be set on R1 or R2/R3 to match.
• The network type is already non-broadcast by default
• Unicast neighbors on R1 and set the OSPF priority to "0" on R2 and R3