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BOOTP is an Internet protocol that can provide network configuration information to diskless workstations, or other workstations if necessary, on a local network. Diskless workstations need to obtain a boot image from a disk on the network because they do not have their own disks from which to obtain this information. BOOTP is also used to initialize IP phones. The boot image provides all the files required to start the operating system on the computer. BOOTP is also used to initialize IP phones.

BOOTP Enhanced what RARP (Reverse Address Resolution Protocol does. RARP obtains an IP address only. BOOTP obtains an IP address, a gateway address, and a name server address. BOOTP is designed for LANs and bridged networks. It can be used across routed internetworks if the routers support BOOTP forwarding.

When a workstation boots, it broadcasts a BOOTP message on the network. A BOOTP server receives this message, obtains the configuration information for the designated computer, and returns it to the computer. The booting system does not have an IP address when it sends out a BOOTP message. Instead, the hardware address of the NIC (network interface card) is placed in the message and the BOOTP server returns its reply to this address.

Information returned by the BOOTP server to the booting computer includes its IP address, the IP address of the server, the host name of the server, and the IP address of a default router. It also specifies the location of a boot image that the booting computer can obtain in order to complete its startup operation.

Note that administrators must manually configure the information on a BOOTP server. An IP address must be matched to the MAC (medium access control) addresses of computers on the network. To minimize this configuration requirement, DHCP (Dynamic Host Configuration Protocol) was developed to automatically allocate IP addresses to clients. Basically, BOOTP makes a request for IP Information while DHCP fulfills that request.

The following Internet RFCs discuss BOOTP and related protocols.

• RFC 951 (The Bootstrap Protocol, September 1985)


• RFC 1534 (Interoperation Between DHCP and BOOTP, October 1993)


• RFC 1542 (Clarifications and Extensions for the Bootstrap Protocol, October 1993)


• RFC 2132 (DHCP Options and BOOTP Vendor Extensions, March 1997)

Copyright (c) 2001 Tom Sheldon and Big Sur Multimedia.
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