Background

• BOOTP was developed in 1985 to create procedures for the remote management of diskless workstations. Before BOOTP, network administrators had to visit every workstation with a floppy disk to boot up the workstation and enter its configuration details. Diskless workstations had two big disadvantages for administrators. First, the absence of a fixed disk made it impossible to boot the workstation off a traditional bootstrap sector. Computers automatically load certain files into memory on startup and execute them -- this is the bootstrap sector. The second problem was that the workstation was unable to store any settings, such as a network address. Until the workstation had an address, it could not communicate with any server.
  
  

Purpose

• BOOTP solved the two main problems of diskless workstations. A small program, written onto the network card of the computer, always executed when power reached the card. The program sent a request for an IP address and then used that to send a request for a boot file. Thus, both address allocation and boot-up process could be sent over the network automatically.
  
  

DHCP

• The Dynamic Host Configuration Protocol was developed in 1993. It expanded the message structure of BOOTP and removed the need for a configuration file by including those parameters in the message. DHCP's main work is as a method of distributing IP addresses dynamically. IP addresses are running out and Internet service providers and large networks rarely allocate permanent IP addresses. Instead, they maintain a pool of addresses for the network and allocate an address to a computer only for the duration of its connection. Each address can then be reused and the network does not need as many addresses as it has computers. DHCP, with its single phase, is a more efficient method of distributing dynamic IP addresses.
  
  

Benefit of BOOTP

• BOOTP is not as efficient a method of delivering IP addresses as DHCP; however, BOOTP can deliver more than just an address because of its second phase of delivering a configuration file. DHCP can only offer this capability as part of the Preboot Execution Environment, known as PXE. Although DHCP is a more efficient method than BOOTP for distributing IP addresses, BOOTP is a simpler method than PXE for distributing bootstrap programs.