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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide
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Chapter32 Configuring IP Unicast Routing Configuring OSPF
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. Becau se l oopba ck int erfac e s 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.
Monitoring OSPF
You can display specific statistics such as the contents of IP routing tables, caches, and databases.
Table32-6 lists some of t he privileged EXEC commands for displaying statistics. For more show ip ospf
database privileged EXEC command options and for explanations of fields in the resulting display, see
the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols, Release 12.2.
Step3 timers lsa-group-pacing seconds Change the group pacing of LSAs.
Step4 end Return to privileged EXEC mode.
Step5 show running-config Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface loopback 0 Create a loopback interface, and enter interface configuration mode.
Step3 ip address address mask Assign an IP address to this interface.
Step4 end Return to privileged EXEC mode.
Step5 show ip interface Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.