Command Manual – Routing Protocol 
Quidway S8500 Series Routing Switches  Chapter 4  Integrated IS-IS Configuration Commands
 
Huawei Technologies Proprietary 
4-38 
y: Interval (in milliseconds) between a trigger operation and an SPF calculation 
operation. It ranges from 1 to 120,000 and defaults to 5,500. 
z: Interval (in milliseconds) between two successive SPF calcaulation operations. It 
ranges from 1 to 120,000 and defaults to 5,500. 
level-1: Sets Level-1 SPF calculation interval only.  
level-2: Sets Level-2 SPF calculation interval only. 
If the level is not specified, it defaults to setting Level-1 SPF calculation interval. 
Description 
Use the timer spf command to configure the interval for the SPF calculation of 
corresponding level. 
Use the undo timer spf command to restore the system default value. 
In IS-IS, when the LSDB of the corresponding level is changed, SPF calculation is 
required. However, if the SPF calculation is performed too frequently, the system 
efficiency will be lowered. By setting a proper interval for performing SPF calculation, 
you can avoid the above situation. This setting can be made according to actual 
conditions. 
Example 
# Set the SPF calculation interval of the router to 3, 100 and 500 seconds.  
[Quidway-isis] timer spf 3 100 500