Implementing 802.1X would have best prevented this avenue of attack. 802.1X is a standard that provides port-based network access control (PNAC), which means that it authenticates devices before allowing them to access network resources through a physical or wireless port. 802.1X can prevent unauthorized devices from obtaining valid IP addresses or accessing sensitive data by requiring them to provide credentials, such as a username and password, a certificate, or a token. 802.1X can also dynamically assign VLANs or firewall rules based on the device identity or role.