17-2 timers spf delay interval

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17-2 timers spf delay interval

Syntax Description:

  • delay ” The delay, in seconds, between when a topology change is received and the shortest path first (SPF) calculation begins. The range of values is 0 to 4,294,967,295 seconds. The default time is 5 seconds.

  • interval ” The interval, in seconds, between successive SPF calculations. The range of values is 0 to 4,294,967,295 seconds. The default time is 10 seconds.

Purpose: When a change in the OSPF topology occurs, the OSPF process will run an SPF calculation. The delay parameter of this command sets the delay time between receipt of an OSPF topology change and the start of the SPF calculation. The interval parameter is the wait time between two SPF calculations. If the SPF calculation is being executed fre-quently, there may be a flapping interface in the network, causing OSPF to send frequent topology changes.

Initial Cisco IOS Software Release: 10.3

Configuration Example: Modifying the LSA Group Pacing

The SPF timers can be modified with the timers spf router configuration command, as shown in the following listing.

 Router A  router ospf 1   log-adjacency-changes    timers spf 8 16    network 1.1.1.1 0.0.0.0 area 1   network 10.1.1.0 0.0.0.3 area 0  
Verification

The SPF timer values can be verified with the show ip ospf command.

 rtrA#  show ip ospf  Routing Process "ospf 1" with ID 1.1.1.1 and Domain ID 0.0.0.1  Supports only single TOS(TOS0) routes  Supports opaque LSA  It is an area border router  SPF schedule delay 8 secs, Hold time between two SPFs 16 secs  Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs  Number of external LSA 0. Checksum Sum 0x0  Number of opaque AS LSA 0. Checksum Sum 0x0  Number of DCbitless external and opaque AS LSA 0  Number of DoNotAge external and opaque AS LSA 0  Number of areas in this router is 2. 2 normal 0 stub 0 nssa  External flood list length 0     Area BACKBONE(0)         Number of interfaces in this area is 1         Area has no authentication         SPF algorithm executed 24 times         Area ranges are         Number of LSA 16. Checksum Sum 0x8759C         Number of opaque link LSA 0. Checksum Sum 0x0         Number of DCbitless LSA 0         Number of indication LSA 0         Number of DoNotAge LSA 0         Flood list length 0     Area 1         Number of interfaces in this area is 1         Area has no authentication         SPF algorithm executed 12 times         Area ranges are         Number of LSA 3. Checksum Sum 0x14E8B         Number of opaque link LSA 0. Checksum Sum 0x0         Number of DCbitless LSA 0         Number of indication LSA 0         Number of DoNotAge LSA 0         Flood list length 0 
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Cisco[r] OSPF Command and Configuration Handbook
Cisco OSPF Command and Configuration Handbook (paperback)
ISBN: 1587055406
EAN: 2147483647
Year: 2002
Pages: 236

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