IP OSPF Network Broadcast
This command manually sets the OSPF network type to broadcast, this is a default for ethernet links.
The Broadcast network type has a DR election.
Router(config-if)#ip ospf network broadcast
In this example, we will configure R4’s frame-relay link to use the broadcast network type
First we’ll configure OSPF on R1, R3, and R4 for all interfaces.
R4(config-router)#router ospf 1 R4(config-router)#network 0.0.0.0 0.0.0.0 area 0
After a couple minutes R4 still doesn’t have any adjacencies
R4(config-router)#do show ip ospf neighbor R4(config-router)#
Notice that the OSPF network type is non_broadcast so it will require unicast updates.
R4(config)#do show ip ospf interface s0/0 Serial0/0 is up, line protocol is up Internet Address 10.4.4.4/24, Area 0 Process ID 1, Router ID 18.104.22.168, Network Type NON_BROADCAST, Cost: 64 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 22.214.171.124, Interface address 10.4.4.4 No backup designated router on this network Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5 oob-resync timeout 120 Hello due in 00:00:25 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 0 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s)
After we configure the broadcast network type on all routers, the adjacencies form.
R4(config)#int s0/0 R4(config-if)#ip ospf network broadcast R4(config-if)# *Mar 1 01:02:07.627: %OSPF-5-ADJCHG: Process 1, Nbr 126.96.36.199 on Serial0/0 from LOADING to FULL, Loading Done R4(config-if)# *Mar 1 01:02:11.707: %OSPF-5-ADJCHG: Process 1, Nbr 188.8.131.52 on Serial0/0 from LOADING to FULL, Loading Done R4(config-if)#do show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 184.108.40.206 1 FULL/DROTHER 00:00:30 10.4.4.1 Serial0/0 220.127.116.11 1 FULL/DR 00:00:30 10.4.4.3 Serial0/0 R4(config-if)#