Dell Force10 S25N-S50N FTOS Command Line Reference Guide FTOS 8.4.2.7 E-Series - Page 860

www.dell.com | support.dell.com Parameters level-l level-2 interval seconds initial_wait_interval seconds second_wait_interval seconds (OPTIONAL) Enter the keyword level-1 to apply the configuration to Level-1 SPF calculations. (OPTIONAL) Enter the keyword level-2 to apply the configuration to Level-2 SPF calculations. Enter the maximum number of seconds between SPF calculations. Range: 0 to 120 seconds Default: 10 seconds (OPTIONAL) Enter the initial wait time, in seconds, before running the first SPF calculations. Range: 0 to 120 seconds Default: 5 second (OPTIONAL) Enter the wait interval, in seconds, between the first and second SPF calculations. Range: 0 to 120 seconds Default: 5 seconds Defaults Defaults as above Command Modes ROUTER ISIS (for IPv4) CONFIGURATION-ROUTER-ISIS-ADDRESS-FAMILY-IPV6 (for IPv6) Command History Version 7.8.1.0 Version 7.5.1.0 Introduced to support MT ISIS Expanded to support SPF Throttling Enhancement Usage Information This command spf-interval in CONFIG-ROUTER-ISIS-AF-IPV6 mode is used for IPv6 Multi-Topology route computation only. If using single topology mode, use the spf-interval command in CONFIG-ROUTER-ISIS mode for both IPv4 and IPv6 route computations. SPF throttling slows down the frequency at which route calculation are performed during network instability. Even though throttling route calculations slows down network convergence, not throttling can result in a network not functioning as expected. If network topology is unstable, throttling slows down the scheduling of route calculations until the topology regains its stability. The first route calculation is controlled by the initial wait interval and the second calculation is controlled by the second wait interval. Each subsequent wait interval is twice as long as the previous one until the wait interval reaches the maximum wait time specified (interval seconds). Once the network calms down and there are no triggers for two times the maximum interval, fast behavior is restored (the initial wait time). 860 | Intermediate System to Intermediate System (IS-IS)