Enabling unauthorized DHCP server detection

Unauthorized DHCP servers on a network may assign wrong IP addresses to DHCP clients.

With unauthorized DHCP server detection enabled, the DHCP server checks whether a DHCP request contains Option 54 (Server Identifier Option). If yes, the DHCP server records the IP address of each detected DHCP server that assigned an IP address to a requesting DHCP client in the option, and records the receiving interface. The administrator can use this information to check for unauthorized DHCP servers.

With the unauthorized DHCP server detection enabled, the switch logs each detected DHCP server once. The administrator can use the log information to find unauthorized DHCP servers.

To enable unauthorized DHCP server detection: