Changing Lsa Group Pacing; Configuring A Loopback Interface - Cisco Catalyst 3750 Software Configuration Manual
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Also See for Catalyst 3750:
- Command reference manual (1154 pages) ,
- Hardware installation manual (231 pages) ,
- Message manual (120 pages)
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Chapter 28
Configuring IP Unicast Routing
Changing LSA Group Pacing
The OSPF LSA group pacing feature allows the router to group OSPF LSAs and pace the refreshing,
check-summing, and aging functions for more efficient router use. This feature is enabled by default with
a 4-minute default pacing interval, and you will not usually need to modify this parameter. The optimum
group pacing interval is inversely proportional to the number of LSAs the router is refreshing,
check-summing, and aging. For example, if you have approximately 10,000 LSAs in the database,
decreasing the pacing interval would benefit you. If you have a very small database (40 to 100 LSAs),
increasing the pacing interval to 10 to 20 minutes might benefit you slightly.
Beginning in privileged EXEC mode, follow these steps to configure OSPF LSA pacing:
Command
Step 1
configure terminal
Step 2
router ospf process-id
Step 3
timers lsa-group-pacing seconds
Step 4
end
Step 5
show running-config
Step 6
copy running-config startup-config
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:
Command
Step 1
configure terminal
Step 2
interface loopback 0
Step 3
ip address address mask
Step 4
end
Step 5
show ip interface
Step 6
copy running-config startup-config
Use the no interface loopback 0 global configuration command to disable the loopback interface.
78-15870-01
Purpose
Enter global configuration mode.
Enable OSPF routing, and enter router configuration mode.
Change the group pacing of LSAs.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Purpose
Enter global configuration mode.
Create a loopback interface, and enter interface configuration mode.
Assign an IP address to this interface.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3750 Metro Switch Software Configuration Guide
Configuring OSPF
28-35
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