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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 22 Configuring IP Unicast Routing
Configuring OSPF
This is an example of output from the show ip protocols privileged EXEC command that verifies the
OSPF process ID.
Switch# show ip protocols
<output truncated>
Routing Protocol is "ospf 109"
Invalid after 0 seconds, hold down 0, flushed after 0
Outgoing update filter list for all interfaces is
Incoming update filter list for all interfaces is
Redistributing: ospf 109
Maximum path: 4
Routing for Networks:
131.108.0.0/24 Area 24
Routing Information Sources:
Gateway Distance Last Update
Distance: (default is 110)
OSPF Interface Parameters
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
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter interface configuration mode, and specify the Layer 3 interface
to configure.
Step 3
ip ospf cost
(Optional) Explicitly specify the cost of sending a packet on the
interface.
Step 4
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 5 seconds.
Step 5
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.
Step 6
ip ospf priority number
(Optional) Set priority to help determine the OSPF designated router
for a network. The range is from 0 to 255. The default is 1.
Step 7
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.
Step 8
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.