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
-r 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.
RH Red Hat, Inc. NETREPORT(1)