The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)            9  Host Configuration and TCP/IP Host Configuration Protocols (BOOTP and DHCP)                 9  TCP/IP Dynamic Host Configuration Protocol (DHCP)

TCP/IP Dynamic Host Configuration Protocol (DHCP) 1 2 3 DHCP Address Assignment and Dynamic Address Allocation and Management

DHCP: Building on BOOTP's Strengths

A new host configuration protocol was needed to serve modern networks, which would move away from static, permanent IP address assignment. The IETF supplied this in the form of the Dynamic Host Configuration Protocol (DHCP), first formalized in RFC 1541, October 1993. (Actually, it was really originally specified in RFC 1531 in that same month, but due to minor errors in 1531 the standard was quickly revised and 1541 published.)

Of course, it's not like BOOTP was a bad protocol or anything. It certainly worked well, for what it was capable of doing. It was also already widely deployed. Given these factors, it really made no make sense to start over from scratch with DHCP. This was especially so given that such a decision would have meant dealing with the inevitable “painful” transition, as well as compatibility problems associated with having both BOOTP and DHCP around for many years.

So, instead of tossing out BOOTP, DHCP was built upon it as a foundation. In it simplest form, DHCP consists of two major components: an address allocation mechanism, and a protocol that allows clients to request, and servers to provide, configuration information. DHCP performs both functions in a manner similar to BOOTP, but with improvements.

TCP/IP Dynamic Host Configuration Protocol (DHCP) 1 2 3 DHCP Address Assignment and Dynamic Address Allocation and Management