Router Configuration ExamplesThe following are examples of the configurations contained within the routers shown in Figure 5-21: Hub_Router1# interface Serial 0 ip address 10.0.1.1 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint non-broadcast frame-relay local-dlci 100 ! router ospf 1 network 10.0.1.0 0.0.0.255 area 0 neighbor 10.0.1.2 10 neighbor 10.0.1.3 10 neighbor 10.0.1.4 10 Spoke_Router2# interface Serial 0 ip address 10.0.1.2 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint non-broadcast frame-relay local dlci 101 ! router ospf 1 network 10.0.1.0 0.0.0.255 area 0 network 10.2.0.0 0.0.255.255 area 2 neighbor 10.0.1.1 10 Spoke_Router3# interface Serial 0 ip address 10.0.1.3 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint non-broadcast frame-relay local-dlci 103 ! router ospf 1 network 10.0.1.0 0.0.0.255 area 0 network 10.3.0.0 0.0.255.255 area 3 neighbor 10.0.1.1 10 Spoke_Router4# interface Serial 0 ip address 10.0.1.4 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint non-broadcast frame-relay local-dlci 104 ! router ospf 1 network 10.0.1.0 0.0.0.255 area 0 network 10.4.0.0 0.0.255.255 area 4 neighbor 10.0.1.1 10
The following capture from a router occurred before the circuit went active. Check the State. The following example highlights the important fields that you would use in troubleshooting an OSPF link-state problem: Hub_router1#show ip ospf interface serial 0 Serial0 is up, line protocol is up Internet Address 10.0.1.1/24, Area 0 Process ID 10, Router ID 10.0.1.1, Network Type POINT_TO_MULTIPOINT, Cost: 64 DoNotAge LSA allowed. Transmit Delay is 1 sec, State DOWN, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 After the OSPF state goes active, the capture from the router is as follows: Hub_router1#show ip ospf interface serial 0 Serial0 is up, line protocol is up Internet Address 10.0.1.1/24, Area 0 Process ID 10, Router ID 10.0.1.1, Network Type POINT_TO_MULTIPOINT, Cost: 64 DoNotAge LSA allowed. Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:01 Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 10.0.1.2 Suppress hello for 0 neighbor(s) Taking a look at the show ip ospf neighbor command for each of the routers will show the following: Hub_Router1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.0.1.2 1 FULL/ - 00:01:30 10.0.1.1 Serial0 10.0.1.3 1 FULL/ - 00:01:30 10.0.1.1 Serial0 10.0.1.4 1 FULL/ - 00:01:30 10.0.1.1 Serial0 The preceding command shows that the state is a full adjacency. Notice that there is no DR or ADR, which is normal and expected behavior for a NBMA media. If the state is anything but FULL, then the adjacencies have not been completely built and there might be a problem with the multicast LSA packets being passed through the interface. Perform the following command to check the state: Spoke_Router2#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.0.1.1 1 FULL/ - 00:01:52 10.0.1.2 Serial0 Spoke_Router3#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.0.1.1 1 FULL/ - 00:01:52 10.0.1.3 Serial0 Spoke_Router4#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.0.1.1 1 FULL/ - 00:01:52 10.0.1.4 Serial0 The following sections provide a definition of the different OSPF states. The Neighbor State Changes (Hello Protocol) The following is a brief description of the possible OSPF neighbor state changes:
|