naapuri

Go implementation and library of Linux's ip monitor neigh which lists ARP/MAC address changes on network interfaces.

Why?

For example:

Automatically add new firewall rules
Automatic inventory discovery
Find intruders
Configure per-mac address VLANs to your switch(es)
Gather statistics when device(s) are (dis)connected to/from a network
Send MAC address to a database
Send alert(s) when MAC address X is not seen for a while
etc...