| |
|
|
timers throttle spf
Provides for the setting of the OSPF SPF exponential backoff timers.
Syntax: timers throttle spf startTime initHoldTime maxHoldTime
startTime
Specifies the Start time in milli-seconds. Valid values: 1 - 600000 ms Default: 1 ms
initHoldTime
Specifies the Initial Hold Time in milli-seconds. Valid values: 1 - 600000 ms. Default: 5000 ms.
maxHoldTime
Specifies the Max Hold Time in milli-seconds. Valid values: 1 - 600000 ms. Default: 5000 ms.
Description: The OSPF SPF exponential backoff functionality limits the number of SPF computations during times of network instability by doubling the delay associated with the SPF run, up to a maximum delay, for the period of instability. When the period of instability ends, the delay is reset to the original value. Three timers are associated SPF exponential backoff: Start Time, Initial Hold Time, and Max Hold Time.
When a topology change is received for the first time, the SPF computation is delayed for the value set by Start Time. IPriori runs an SPF when the Start Time timer expires. When the SPF computation completes, a timer starts with the value of the Initial Hold Time. If there is a topology change during this Initial Hold Time timer run, IPriori runs another SPF computation at the expiration of the Initial Hold Time. At the completion of the SPF computation the Initial Hold Time timer is first doubled and then run again. This process will continue until the Max Hold Time is reached at which time SPF computations will continue to run with a delay of Max Hold Time until an hold timer expires with no topology change taking place during the length of the timer. When that happens, the hold timer value returns to the value set by the Start Time.
Use the timers throttle spf startTime initHoldTime maxHoldTime command to configure OSPF SPF exponential backoff.
Use the no timers throttle spf command to reset the OSPF backoff to default values.
The timers throttle spf and timers-spf command can not be configured at the same time. Which ever configurations is the last entered will always override the former configuration. If an SPF computation is pending for received changes and a configuration change takes place from one of these commands to another, an SPF computation will be run immediately with the timer values of the latter command configuration taking affect at the end of the SPF computation.
Factory Default: Disabled.
Command Mode: Router configuration.
Example 1: In the following example the delayValue stays at the default value of 0 seconds, while the holddownValue is changed to 7 seconds:
router(config)#router ospf 12
router(config-router)#timers spf 0 7
router(config-router)end
router#
Example 2: In the following example: SPF timer values are reset to defaults:
router(config)#router ospf 12
router(config-router)#no timers spf
router(config-router)end
router#
Related Commands: show ip ospf
| |
|
|
Copyright © 2004
Avici Systems Inc.
Avici® and TSR®
is a registered trademark of Avici Systems Inc.
IPriori™, Composite Links™, SSR™, QSR, and NSR® are
trademarks of Avici Systems Inc.
Source
File Name: ospf.fm
HTML File Name: ospf32.html
Last Updated: 05/10/04 at 16:34:58