ArpON (Arp handler inspectiON) is a portable handler daemon that make ARP secure in order to avoid the Man In The Middle through ARP Spoofing/Poisoning & co attacks. It detects and blocks also Man In The Middle through DHCP Spoofing, DNS Spoofing, Session Hijacking and SSL Hijacking through ARP Spoofing/Poisoning attack.
http://arpon.sourceforge.net