Description:

This software is used for monitoring ethernet networks. It listens on a network
interface (without using 'promiscuous' mode) and catches all conversations of
MAC address to IP request. It then compares the mac addresses it detected with
a pre-configured list of authorized MAC addresses. If the MAC is not in list,
arpalert launches a pre-defined user script with the MAC address and IP address
as parameters. This software can run in daemon mode; it's very fast (low CPU
and memory consumption). It responds at signal SIGHUP (configuration reload)
and at signals SIGTERM, SIGINT, SIGQUIT and SIGABRT (arpalert stops itself).