BOOTP is the 'Bootstrap Protocol and described in RFC 951. It uses TCP and UDP on port 67 for the server and 68 for the client.
It is an Internet protocol that enables a diskless workstation to discover its own IP address, the IP address of a BOOTP server on the network, and a file to be loaded into memory to boot the machine. This enables the workstation to boot without requiring a hard or floppy disk drive.
Related: Linux Terminal Server Project