Open Shortest Path First (OSPFv2 and OSPFv3) | 709Enable OSPFv2 on interfacesEach interface must have OSPFv2 enabled on it. It must be configured for Layer 3 protocol, and not beshutdown. OSPFv2 can also be assigned to a loopback interface as a virtual interface.OSPF functions and features, such as MD5 Authentication, Grace Period, Authentication Wait Time, etc,are assigned on a per interface basis.Figure 32-9 presents an example of assigning an IP address to an interface and then assigning an OSPFv2area that includes that Layer-3 interface’s IP address.Figure 32-9. Configuring an OSPF Area ExampleForce 10 recommends that the OSPFv2 Router ID be the interface IP addresses for easier management andtroubleshooting.Use the show config command in CONFIGURATION ROUTER OSPF mode to view the configuration.OSPF, by default, sends hello packets out to all physical interfaces assigned an IP address that are a subsetof a network on which OSPF is enabled. Use the show ip ospf interface command (Figure 410) to viewthe interfaces currently active and the areas assigned to the interfaces.Note: If using features like MD5 Authentication, ensure all the neighboring routers are alsoconfigured for MD5.FTOS#(conf)#int gi 4/44FTOS(conf-if-gi-4/44)#ip address 10.10.10.10/24FTOS(conf-if-gi-4/44)#no shutdownFTOS(conf-if-gi-4/44)#exFTOS(conf)#router ospf 1FTOS(conf-router_ospf-1)#network 1.2.3.4/24 area 0FTOS(conf-router_ospf-1)#network 10.10.10.10/24 area 1FTOS(conf-router_ospf-1)#network 20.20.20.20/24 area 2FTOS(conf-router_ospf-1)#FTOS#Assign Layer-3 interfacewith IP Address andno shutdownAssign interface’sIP Address to an Area
