bootp

BOOTP (Bootstrap Protocol) is a network protocol designed to assist devices in obtaining their initial network configuration parameters, such as an IP address, subnet mask, default gateway, and DNS server, during the booting process. It operates at the application layer of the OSI model and is closely related to DHCP (Dynamic Host Configuration Protocol), which it predates.

BOOTP was introduced in the early 1980s as part of the original TCP/IP suite to simplify network administration by automating the assignment of IP addresses and other configuration details. Unlike DHCP, which supports dynamic IP assignment and lease management, BOOTP primarily relies on a static mapping between hardware addresses (MAC addresses) and IP addresses stored on a central server. This makes BOOTP less flexible but more deterministic in environments where device identities are fixed.

The BOOTP process begins when a client device broadcasts a BOOTP request packet across the local network. The packet contains the client’s MAC address and other identifying information. A BOOTP server, typically running on a dedicated host, responds with a BOOTP reply containing the required configuration parameters. The client then uses these details to initialize its network interface and proceed with the booting process, often loading an operating system image from a server via protocols like TFTP (Trivial File Transfer Protocol).

While BOOTP remains functional, it has largely been superseded by DHCP due to its limitations in scalability and dynamic configuration. However, it is still used in legacy systems or specialized environments where static assignments are preferred. BOOTP operates over UDP (User Datagram Protocol) using port 67 for servers and port 68 for clients, ensuring efficient communication without the overhead of TCP.