OSPF troubleshooting - No route update

R1 and R3 form a neighbor relationship but they are not exchanging route.

R3_CME_2801#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/BDR 00:01:41 172.31.77.1 Serial0/3/0
R3_CME_2801#sh ip route ospf

R3_CME_2801#

What is the problem?

Solution: Mismatch in IP OSPF network type -

- make sure you have the same network type on both routers

Sh ip ospf int s0/3/0

- correct the mismatch network
conf t
int s0/3/0
ip ospf network point-to-point





R3_CME_2801#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/BDR 00:01:41 172.31.77.1 Serial0/3/0
R3_CME_2801#sh ip route ospf

R3_CME_2801#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3_CME_2801(config)#int s0/3/0
R3_CME_2801(config-if)#ip ospf net
R3_CME_2801(config-if)#ip ospf network point-to-multipoint
R3_CME_2801(config-if)#
*Jul 10 16:07:56.321: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Serial0/3/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Jul 10 16:07:56.569: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Serial0/3/0 from LOADING to FULL, Loading Done
R3_CME_2801(config-if)#do sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 0 FULL/ - 00:01:57 172.31.77.1 Serial0/3/0
R3_CME_2801(config-if)#do sh ip route ospf
172.31.0.0/16 is variably subnetted, 3 subnets, 2 masks
O 172.31.77.2/32 [110/128] via 172.31.77.1, 00:00:27, Serial0/3/0
O 172.31.77.1/32 [110/64] via 172.31.77.1, 00:00:27, Serial0/3/0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
O 10.254.0.0/24 [110/74] via 172.31.77.1, 00:00:27, Serial0/3/0
R3_CME_2801(config-if)#