Configuring OSPF for NBMA Networks

You can configure OSPF nonbroadcast multiaccess (NBMA) networks. You can configure your OSPF network type as NBMA, regardless of the default medium. This configuration is useful when, for example, you have routers in your network that do not support multicast addressing.

You must use the neighbor command to specify the router’s OSPF neighbors.

To configure OSPF for an NBMA network:

1. Configure an interface network type as NBMA for OSPF.
   host1(config-subif)#ip ospf network non-broadcast
2. Exit Interface Configuration mode. Enter Global Configuration mode.
   host1(config-subif)#exit
3. Configure an OSPF routing process, and enter Router Configuration mode.
   host1(config)#router ospf 5
4. Specify an OSPF neighbor, and optionally assign a priority number or poll interval to the neighbor.
   host1(config-router)#neighbor 10.12.14.1 priority 5 poll-interval 180
5. Repeat Step 4 for each neighbor in the OSPF network.

If you want to configure the network type for a specific interface or OSPF area, rather than for all OSPF interfaces, you can use the address network command rather than the ip ospf network command.