3Com Switch 8800 Configuration Guide Chapter 20 Integrated IS-IS Configuration20-23By default, SPF calculation is not divided into slices but runs to the end once, which canalso be implemented by setting the seconds argument to 0.After slice calculation is set, the routes that are not processed once will be calculated inone second.Normally, the user is not recommended to modify the default configuration. When thenumber of routes is between 150,000 and 200,000, it is recommended to set theseconds argument to 1, that is, the duration time for SPF calculation each time is 1second.III. Setting SPF to release CPU activelyTo prevent SPF calculation from occupying the system resources for a long time, whichaffects the response speed of the console, SPF can be set to automatically release thesystem CPU resources after processing a certain number of routes and theunprocessed routes will be calculated in one second.Perform the following configuration in IS-IS view.Table 20-32 Set SPF to release CPU activelyOperation CommandSpecify the number of routes to processbefore releasing CPU spf-delay-interval numberRestore the default configuration undo spf-delay-intervalBy default, CPU is released once when every 5000 routes are processed by the SPF ofIS-IS.20.2.24 Enabling/Disabling the Interface to Send PacketsTo prevent the IS-IS routing information from being obtained by some router in a certainnetwork, the silent-interface command can be used to prohibit sending IS-IS packetsvia the interface connecting with the router.Perform the following configuration in IS-IS view.Table 20-33 Enable/Disable the interface to send IS-IS packetsOperation CommandDisable the interface to send IS-ISpacketssilent-interface silent-interface-typesilent-interface-numberEnable the interface to send IS-ISpacketsundo silent-interface silent-interface-typesilent-interface-numberBy default, the interface is allowed to receive and send IS-IS packets.
