Check if you have packets already installed: dpkg –status libpcap0.8   dpkg –status arpwatch If not already installed, install packets: apt-get install libpcap0.8 apt-get install arpwatch Create empty file for storing host information: vi /var/lib/arpwatch/arp.dat Configure parameters: vi /etc/arpwatch.conf insert line like this: eth0 -a -n 124.18.0.0/24 -m [email protected] Restart arpwatch for new configuration /etc/init.d/arpwatch restart […]