The DHCP_OPTION_ID structure specifies the DHCP option identifier for an option configured on the DHCP server. The identifier is a unique integer that identifies the option defined for a user class and a vendor class. The option ID range for DHCPv4 options is 1 to 255, while the option ID range for DHCPv6 options is 0 to 65536.
This type is declared as follows:
typedef DWORD DHCP_OPTION_ID;