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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)                      9  DHCP Messaging, Message Types and Formats

DHCP Options, Option Format and "Option Overloading" 1 2 3 4 5 6 DHCP Client/Server Implementation, Features and Issues

BOOTP vendor information fields are used to carry additional vendor-independent configuration parameters. These were used as the basis for DHCP options, which extend the concept to include parameters used to manage the operation of DHCP as a whole, as described in the preceding topic. Since BOOTP vendor information fields and DHCP options are essentially the same (except for the DHCP-specific fields), they are described in the same TCP/IP standard, and hence, in this single Guide topic.

Below I have included a number of tables, organized by the RFC 2132 option categories, that list each of the DHCP options / BOOTP vendor information fields. I have shown each option's Code value, and the length of the Data subfield for the option, in bytes. I have then provided the formal name of the option and a brief description of how it is used. For simplicity, in the tables below I say just “options”; please read “option” as “option / vendor information field”, since they are the same (except, again, the DHCP-specific options.)

There are a lot of options in these tables, and some of them define parameters that are used by somewhat obscure protocols that I may not cover in this Guide, so don't be put off if the brief description is not enough for you to completely understand how each and every option is used. Other options will seem quite familiar to you based on other discussions in this Guide. Note in particular that many of the original BOOTP vendor information fields that are used to communicate the addresses of certain types of servers are now archaic and may no longer be used.

DHCP Options, Option Format and "Option Overloading" 1 2 3 4 5 6 DHCP Client/Server Implementation, Features and Issues