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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter38 Configuring IP Unicast Routing
Configuring OSPF
This example shows how to configure an OSPF routing process and assign it a process number of 109:
Switch(config)# router ospf 109
Switch(config-router)# network 131.108.0.0 255.255.255.0 area 24
Configuring OSPF Interfaces
You can use the ip ospf interface configuration commands to modify interface-specific OSPF
parameters. You are not required to modify any of these parameters, but some interface parameters (hello
interval, dead interval, and authentication key) must be consistent across all routers in an attached
network. If you modify these parameters, be sure all routers in the network have compatible values.
Note The ip ospf interface configuration commands are all optional.
Beginning in privileged EXEC mode, follow these steps to modify OSPF interface parameters:
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Enter interface configuration mode, and specify the Layer 3 interface
to configure.
Step3 ip ospf cost (Optional) Explicitly specify the cost of sending a packet on the
interface.
Step4 ip ospf retransmit-interval seconds (Optional) Specify the number of seconds between link state
advertisement transmissions. The range is 1 to 65535 seconds. The
default is 5seconds.
Step5 ip ospf transmit-delay seconds (Optional) Set the estimated number of seconds to wait before
sending a link state update packet. The range is 1 to 65535 seconds.
The default is 1 second.
Step6 ip ospf priority number (Optional) Set priority to help find the OSPF designated router for a
network. The range is from 0 to 255. The default is 1.
Step7 ip ospf hello-interval seconds (Optional) Set the number of seconds between hello packets sent on
an OSPF interface. The value must be the same for all nodes on a
network. The range is 1 to 65535 seconds. The default is 10 seconds.
Step8 ip ospf dead-interval seconds (Optional) Set the number of seconds after the last device hello
packet was seen before its neighbors declare the OSPF router to be
down. The value must be the same for all nodes on a network. The
range is 1 to 65535 seconds. The default is 4 times the hello interval.
Step9 ip ospf authentication-key key (Optional) Assign a password to be used by neighboring OSPF
routers. The password can be any string of keyboard-entered
characters up to 8 bytes in length. All neighboring routers on the
same network must have the same password to exchange OSPF
information.
Step10 ip ospf message digest-key keyid md5 key (Optional) Enable MDS authentication.
•keyid—An identifier from 1 to 255.
•key—An alphanumeric password of up to 16 bytes.