modified to use kqueue/kevent and sysctl.
The ifstated daemon runs commands in response to network state changes,
which it determines by monitoring interface link state or running exter-
nal tests. For example, it can be used with carp(4) to change running
services or to ensure that carp(4) interfaces stay in sync, or with pf(4)
to test server or link availability and modify translation or routing
rules.
PR: ports/74096
Submitted by: Matthew George <mdg@secureworks.net>