36-31
Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 36 Configuring IP Unicast Routing
Configuring OSPF
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:
To return to the default value, use the no timers lsa-group-pacing router configuration command.
Step 7 ip auto-cost reference-bandwidth ref-bw (Optional) Specify an address range for which a single route will be
advertised. Use this command only with area border routers.
Step 8 distance ospf {[inter-area dist1] [inter-area
dist2] [external dist3]}
(Optional) Change the OSPF distance values. The default distance
for each type of route is 110. The range is 1 to 255.
Step 9 passive-interface type number (Optional) Suppress the sending of hello packets through the
specified interface.
Step 10 timers throttle spf spf-delay spf-holdtime
spf-wait
(Optional) Configure route calculation timers.
spf-delay—Delay between receiving a change to SPF
calculation. The range is from 1 to 600000. miliseconds.
spf-holdtime—Delay between first and second SPF calculation.
The range is form 1 to 600000 in milliseconds.
spf-wait—Maximum wait time in milliseconds for SPF
calculations. The range is from 1 to 600000 in milliseconds.
Step 11 ospf log-adj-changes (Optional) Send syslog message when a neighbo r state changes.
Step 12 end Return to privileged EXEC mode.
Step 13 show ip ospf [process-id [area-id]] database Display lists of information related to the OSPF database for a
specific router. For some of the keyword options, see the “Monitoring
OSPF” section on page 36-32.
Step 14 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
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.