IP OSPF Network Point to Multipoint Command on CISCO Router/Switch

Command

IP OSPF Network Point to Multipoint

Use

This command manually sets the OSPF network type to point-to-multipoint. The point-to-multipoint network type does not have an election.

Syntax

Router(config-if)#ip ospf network point-to-multipoint

Example

In this example, we will configure R4’s frame-relay link to use the point-to-multipoint 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 4.5.5.5, Network Type NON_BROADCAST, Cost: 64
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 4.5.5.5, 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 point-to-multipoint network type on all routers, the adjacencies form.

Notice there is no DR information in the show ip ospf neighbor output. This is because the network type doesn’t support elections.

R4(config)#int s0/0
R4(config-if)#ip ospf network point-to-multipoint

*Mar 1 01:16:27.991: %OSPF-5-ADJCHG: Process 1, Nbr 111.111.111.111 on Serial0/0 from LOADING to FULL, Loading Done
*Mar 1 01:16:27.991: %OSPF-5-ADJCHG: Process 1, Nbr 133.133.133.133 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
111.111.111.111 0 FULL/ – 00:01:44 10.4.4.1 Serial0/0
133.133.133.133 0 FULL/ – 00:01:44 10.4.4.3 Serial0/0

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