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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
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Chapter 35 Configuring IP Unicast Routing
Configuring OSPF
Beginning in privileged EXEC mode, follow these steps to configure OSPF LSA pacing:
To return to the default value, use the no timers lsa-group-pacing router configuration command.
Configuring a Loopback Interface
OSPF uses the highest IP address configured on the interfaces as its router ID. If this interface is down
or removed, the OSPF process must recalculate a new router ID and resend all its routing information
out its interfaces. If a loopback interface is configured with an IP address, OSPF uses this IP address as
its router ID, even if other interfaces have higher IP addresses. Because loopback interfaces never fail,
this provides greater stability. OSPF automatically prefers a loopback interface over other interfaces, and
it chooses the highest IP address among all loopback interfaces.
Beginning in privileged EXEC mode, follow these steps to configure a loopback interface:
Use the no interface loopback 0 global configuration command to disable the loopback interface.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 router ospf process-id Enable OSPF routing, and enter router configuration mode.
Step 3 timers lsa-group-pacing seconds Change the group pacing of LSAs.
Step 4 end Return to privileged EXEC mode.
Step 5 show running-config Verify your entries.
Step 6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 interface loopback 0 Create a loopback interface, and enter interface configuration mode.
Step 3 ip address address mask Assign an IP address to this interface.
Step 4 end Return to privileged EXEC mode.
Step 5 show ip interface Verify your entries.
Step 6 copy running-config startup-config (Optional) Save your entries in the configuration file.