Command
IP OSPF Hello Interval
Use
Sets the hello interval on an interface.
Syntax
Router(config-if)#ip ospf hello-interval <seconds>
Example
In this example, the hello interval is modified for int fa0/0 on R1. Here’s the ospf information for fa0/0 before the change. Notice the hello interval set to the default value of 10.
R1#conf t R1(config)#int fa0/0 R1(config-router)#do show ip ospf interface fa0/0 FastEthernet0/0 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0 Process ID 1, Router ID 111.111.111.111, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 111.111.111.111, Interface address 10.1.1.1 Backup Designated router (ID) 2.2.2.2, Interface address 10.1.1.2 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:00 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 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 2.2.2.2 (Backup Designated Router) Suppress hello for 0 neighbor(s)
The hello inteval is changed to 5.
R1(config-if)#ip ospf hello-interval 5
Finally, here’s the ospf information for the interface after the change.
R1(config-if)#do show ip ospf interface fa0/0 FastEthernet0/0 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0 Process ID 1, Router ID 111.111.111.111, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 111.111.111.111, Interface address 10.1.1.1 Backup Designated router (ID) 2.2.2.2, Interface address 10.1.1.2 Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:00 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 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 2.2.2.2 (Backup Designated Router) Suppress hello for 0 neighbor(s)