RFC 1542 (rfc1542) - Page 2 of 23

Clarifications and Extensions for the Bootstrap Protocol

RFC 1542        Clarifications and Extensions for BOOTP     October 1993


   3.4 Interpretation of the 'giaddr' field........................ 11
   3.5 Vendor information "magic cookie"........................... 12
   4. BOOTP Relay Agents........................................... 13
   4.1 General BOOTP Processing for Relay Agents................... 14
   4.1.1 BOOTREQUEST Messages...................................... 14
   4.1.2 BOOTREPLY Messages........................................ 17
   5. BOOTP Server Behavior........................................ 18
   5.1 Reception of BOOTREQUEST Messages........................... 18
   5.2 Use of the 'secs' field..................................... 19
   5.3 Use of the 'ciaddr' field................................... 19
   5.4 Strategy for Delivery of BOOTREPLY Messages................. 20
   Acknowledgements................................................ 21
   References...................................................... 22
   Security Considerations......................................... 23
   Author's Address................................................ 23

1. Introduction

   The Bootstrap Protocol (BOOTP) is a UDP/IP-based protocol which
   allows a booting host to configure itself dynamically and without
   user supervision.  BOOTP provides a means to notify a host of its
   assigned IP address, the IP address of a boot server host, and the
   name of a file to be loaded into memory and executed [1].  Other
   configuration information such as the local subnet mask, the local
   time offset, the addresses of default routers, and the addresses of
   various Internet servers can also be communicated to a host using
   BOOTP [2].

   Unfortunately, the original BOOTP specification [1] left some issues
   of the protocol open to question.  The exact behavior of BOOTP relay
   agents formerly called "BOOTP forwarding agents") was not clearly
   specified.  Some parts of the overall protocol specification actually
   conflict, while other parts have been subject to misinterpretation,
   indicating that clarification is needed.  This memo addresses these
   problems.

   Since the introduction of BOOTP, the IEEE 802.5 Token Ring Network
   has been developed which presents a unique problem for BOOTP's
   particular message-transfer paradigm.  This memo also suggests a
   solution for this problem.

   NOTE: Unless otherwise specified in this document or a later
   document, the information and requirements specified througout this
   document also apply to extensions to BOOTP such as the Dynamic Host
   Configuration Protocol (DHCP) [3].






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