Configuring TCP/IP Options
The messages clients and servers broadcast to each other allow you to set TCP/IP options that clients can obtain by default when they obtain a lease or can request if they need additional information. It is important to note, however, that the types of information you can add to DHCP messages is limited in several ways:
DHCP messages are transmitted using User Datagram Protocol (UDP), and the entire DHCP message must fit into the UDP datagram. On Ethernet with 1500-byte datagrams, this leaves 1236 bytes for the body of the message (which contains the TCP/IP options).
BOOTP messages have a fixed size of 300 bytes as set by the original BOOTP standard. Any clients using BOOTP are likely to have their TCP/IP options truncated. ...