Interoperation Between DHCP and BOOTP (RFC1534)

Network Working Group R. Droms Request for Comments: 1534 Bucknell University Category: Standards Track October 1993

Interoperation Between DHCP and BOOTP

Status of this Memo

This RFC specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Abstract

DHCP provides a superset of the functions provided by BOOTP. This document describes the interactions between DHCP and BOOTP network participants.

1. Introduction

The Dynamic Host Configuration Protocol (DHCP) provides a mechanism for transmitting configuration parameters to hosts using the TCP/IP protocol suite. The format of DHCP messages is based on the format of BOOTP messages, so that, in certain circumstances, DHCP and BOOTP participants may exchange messages. This document specifies the ways in which DHCP and BOOTP participants may interoperate.

DHCP introduces a small change in terminology intended to clarify the meaning of one of the fields. What was the "vendor extensions" field in BOOTP has been re-named the "options" field in DHCP. Similarly, the tagged data items that were used inside the BOOTP "vendor extensions" field, which were formerly referred to as "vendor extensions", are now termed simply "options". This document will refer to BOOTP vendor extensions and DHCP options uniformly as "options".

Throughout this document, DHCP messages that include a ’DHCP message type’ option will be referred to by the type of the message; e.g., a DHCP message with ’DHCP message type’ option type 1 will be referred to as a "DHCPDISCOVER" message.

Droms [Page 1]

RFC 1534 Interoperation Between DHCP and BOOTP October 1993

2. BOOTP clients and DHCP servers

The format of DHCP messages is defined to be compatible with the format of BOOTP messages, so that existing BOOTP clients can interoperate with DHCP servers. Any message received by a DHCP server that includes a ’DHCP message type’ (51) option is assumed to have been sent by a DHCP client. Messages without the DHCP Message Type option are assumed to have been sent by a BOOTP client. Support of BOOTP clients by a DHCP server is optional at the discretion of the local system administrator. If a DHCP server that is not configured to support BOOTP clients receives a BOOTREQUEST message from a BOOTP client, that server silently discards the BOOTREQUEST message.

If a DHCP server is configured to support BOOTP clients, it may be configured to supply static addresses, automatic addresses or both. Static addresses are those that have been previously assigned by a system administrator and are stored in a database available to the DHCP server. Automatic addresses are those selected by the DHCP server from its pool of unassigned addresses.

Since BOOTP clients may not be prepared to receive automatic addresse...