Abstract: A method and system for preventing address resolution protocol (ARP) cache poisoning in a network system with multiple hosts. Multiple hosts representing and/or located in separate local area networks (LANS) are tapped (via a shared agreement) to utilize a trusted ARP cache for each LAN represented. Whenever a new ARP response is detected in one network, a request for validation is sent to a separate host in a different network. The separate host initiates a verification process for the ARP, which involves checking whether duplication of one of the IP address or MAC address of the ARP response exists within the address pairings in the ARP cache. If the ARP response is not validated, then the trusted ARP cache is not updated and the system administrator is notified of the failed attempt.