Interval is a Cardinal property that represents the number of milliseconds allowed to elapse while checking the current IPAddresses for the local system, or between executions of the Thread for the component. 

The default value for Interval is IdIPAddrMonInterval, as assigned during initialization of the component. 

Interval is assigned to the corresponding property in the TIdIPAddrMonThread instance in Thread that is created when Active is changed to True. 

During execution of the Thread, Interval is used to indicate the total number of milliseconds to poll for changes to the IPAddresses for the component. The Thread will poll for changes to the assigned IP addresses every .5 seconds (500 ms) until the number of milliseconds in Interval has elapsed. 

After polling for changes to the IPAddresses for the component, Interval indicates the total number of milliseconds to Sleep until the next execution of the Thread.

Thread Active TIdIPAddrMonThread.Interval