Flush Interval field:
Specifies the amount of time, in seconds, before a routing table entry is removed. The interval should be somewhat longer than the sum of the invalid interval and the holddown interval. This field displays only when the Use protocol defaults field is set to off. After the invalid interval, a route is timed out and marked unreachable. However, the routing table entry for the destination remains, in order to enforce the holddown, if enabled.
Range: 1-65535
Default: 7 times the value in the Update Interval field.