What are some alternatives?
When comparing Arpwatch and ESET Smart Security, you can also consider the following products
TuxCut - TuxCut is a netcut "in Windows OS" like software written in PyQt.
COMODO Internet Security - Download Free Internet Security Software for Complete protection against viruses and attacks of your computers. Know what's new in Comodo Internet Security.
NetCut - NetCut is a Software that helps you admin your network by purely on ARP protocol.
WifiKill - App with ability to block other devices from network
ESET NOD32 Antivirus - Best IT security solutions for your home and business devices. Try ESET antivirus and internet security solutions for Windows, Android, Mac or Linux OS.
CSArp-Netcut - An arpspoofing program that lets users launch spoofed arp requests to disrupt connections in a LAN