netreport - request notification of network interface changes
netreport tells the network management scripts to send a SIGIO signal
to the process which called netreport when any network interface
status changes occur.
Remove the current request (if any) for the calling process.
If a program does not call netreport with the
-r option before it exits, and another process is created with the
same PID before any changes take place in interface status, it
is possible that the new process will receive a spurious SIGIO.