Clarifications and Extensions for the Bootstrap Protocol
RFC 1532
Document | Type |
RFC - Proposed Standard
(October 1993; No errata)
Obsoleted by RFC 1542
Updates RFC 951
Was draft-ietf-dhc-bootp (dhc WG)
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Author | Walter Wimer | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 1532 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group W. Wimer Request for Comments: 1532 Carnegie Mellon University Updates: 951 October 1993 Category: Standards Track Clarifications and Extensions for the Bootstrap Protocol 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 Some aspects of the BOOTP protocol were rather loosely defined in its original specification. In particular, only a general description was provided for the behavior of "BOOTP relay agents" (originally called BOOTP forwarding agents"). The client behavior description also suffered in certain ways. This memo attempts to clarify and strengthen the specification in these areas. In addition, new issues have arisen since the original specification was written. This memo also attempts to address some of these. Table of Contents 1. Introduction................................................. 2 1.1 Requirements................................................ 2 1.2 Terminology................................................. 3 1.3 Data Transmission Order..................................... 4 2. General Issues............................................... 5 2.1 General BOOTP Processing.................................... 5 2.2 Definition of the 'flags' Field............................. 5 2.3 Bit Ordering of Hardware Addresses.......................... 7 2.4 BOOTP Over IEEE 802.5 Token Ring Networks................... 8 3. BOOTP Client Behavior........................................ 9 3.1 Client use of the 'flags' field............................. 9 3.1.1 The BROADCAST flag........................................ 9 3.1.2 The remainder of the 'flags' field........................ 9 3.2 Definition of the 'secs' field.............................. 9 3.3 Use of the 'ciaddr' and 'yiaddr' fields..................... 10 3.4 Interpretation of the 'giaddr' field........................ 11 3.5 Vendor information "magic cookie"........................... 12 4. BOOTP Relay Agents........................................... 13 Wimer [Page 1] RFC 1532 Clarifications and Extensions for BOOTP October 1993 4.1 General BOOTP Processing for Relay Agents................... 13 4.1.1 BOOTREQUEST Messages...................................... 14 4.1.2 BOOTREPLY Messages........................................ 16 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................. 19 Acknowledgements................................................ 21 References...................................................... 21 Security Considerations......................................... 22 Author's Address................................................ 22 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 HostShow full document text