Configuring the IS-IS flooding mechanism

You can configure IS-IS to flood Link State PDUs to other devices in the network before running SPF, thus improving database synchronization by allowing LSP changes to be propagated to neighbors before running SPF. The following task configures the IS-IS fast-flood feature.

About this task

1. Enter the configure terminal command to access global configuration mode.
   

   device# configure terminal

2. Enter the router isis command to enter IS-IS router configuration mode and enable IS-IS on the device.
   

   device(config)# router isis
   

3. Enter the fast-flood command and specify a value to implement IS-IS fast-flood.
   

   device(config-isis-router)# fast-flood 10
   

Example

The following example configures IS-IS to flood 10 LSPs before running SPF.

device# configure terminal
device(config)# router isis
device(config-isis-router)# fast-flood 10