ARP, GARP, and ARP Proxy Made Simple
A simple explanation of ARP, GARP, and ARP Proxy, and a demonstration of simple and straightforward use cases for GARP (Probe-Announce) and ARP Proxy (subnet segmentation).
Specifications:
https://www.ietf.org/rfc/rfc1027.txt
https://www.ietf.org/rfc/rfc5227.txt