This topic describes what BOOTP is, and gives some history about BOOTP and DHCP.
The Bootstrap protocol (BOOTP) is a host configuration protocol that was used before DHCP was developed. BOOTP support is a slimmed down version of DHCP. In BOOTP, clients are identified by their MAC address and are assigned a specific IP address. Essentially, each client in your network is mapped to an IP address. There is no dynamic address assignment, each network client must be identified in the BOOTP configuration, and the clients can only receive a limited amount of configuration information from the BOOTP server.
Because DHCP is based on BOOTP, the DHCP server can support BOOTP clients. If you are currently using BOOTP, you can set up and use DHCP without any impacts to your BOOTP clients. To support BOOTP clients successfully, you must specify the IP address of the bootstrap server and the boot file name option (option 67), and BOOTP support must be turned on for the entire server or various subnets.
Using DHCP to support BOOTP clients is preferred over using a BOOTP server. Even when you use DHCP to support your BOOTP clients, each BOOTP client is essentially being mapped to a single IP address, and that address is therefore not re-usable by another client. The advantage, however, of using DHCP in this case is that there is no need to configure a one-to-one mapping of BOOTP clients to IP addresses. The DHCP server will still dynamically assign an IP addresses to the BOOTP client from the address pool. After the IP address is assigned to the BOOTP client, it is permanently reserved for use by that client until you explicitly delete the address reservation. Eventually, you might want to consider converting your BOOTP clients to DHCP for easier host configuration management.