Configuring OSPF
Enabling OSPF
IPC-225
Cisco IOS IP Configuration Guide
Enabling OSPF
As with other routing protocols, enabling OSPF requires that you create an OSPF routing process,
specify the range of IP addresses to be associated with the routing process, and assign area IDs to be
associated with that range of IP addresses. To do so, use the following commands beginning in global
configuration mode:
Configuring OSPF Interface Parameters
Our OSPF implementation allows you to alter certain interface-specific OSPF parameters, as needed.
You are not required to alter any of these parameters, but some interface parameters must be consistent
across all routers in an attached network. Those parameters are controlled by the ip ospf hello-interval,
ip ospf dead-interval, and ip ospf authentication-key interface configuration commands. Therefore,
be sure that if you do configure any of these parameters, the configurations for all routers on your
network have compatible values.
To specify interface parameters for your network, use the following commands in interface configuration
mode, as needed:
Command Purpose
Step1 Router(config)# router ospf process-id Enables OSPF routing, which places you in router
configuration mode.
Step2 Router(config-router)# network ip-address
wildcard-mask area area-id
Defines an interface on which OSPF runs and define
the area ID for that interface.
Command Purpose
Router(config-if)# ip ospf cost cost Explicitly specifies the cost of sending a packet on an OSPF
interface.
Router(config-if)# ip ospf retransmit-interval
seconds
Specifies the number of seconds between link-state advertisement
(LSA) retransmissions for adjacencies belonging to an OSPF
interface.
Router(config-if)# ip ospf transmit-delay
seconds
Sets the estimated number of seconds required to send a link-state
update packet on an OSPF interface.
Router(config-if)# ip ospf priority
number-value
Sets priority to help determine the OSPF designated router for a
network.
Router(config-if)# ip ospf hello-interval
seconds
Specifies the length of time between the hello packets that the
Cisco IOS software sends on an OSPF interface.
Router(config-if)# ip ospf dead-interval
seconds
Sets the number of seconds that a device must wait before it declares
a neighbor OSPF router down because it has not received a hello
packet.
Router(config-if)# ip ospf authentication-key
key
Assigns a password to be used by neighboring OSPF routers on a
network segment that is using the OSPF simple password
authentication.