INTERNET-DRAFT M. Johnston
draft-ietf-dhc-pxe-options-00.txt Intel Corporation
Expires: February 2004 28 August 2003
DHCP Preboot eXecution Environment (PXE) Suboptions
<draft-ietf-dhc-pxe-options-00.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
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This Internet-Draft will expire on February 1, 2004.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
Define DHCP suboptions being used by PXE and EFI clients.
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Table of Contents
Status of this Memo..............................................1
Copyright Notice.................................................1
Abstract.........................................................1
Table of Contents................................................2
Introduction.....................................................2
1.1. Conventions................................................2
2. Suboption Definitions........................................3
2.1. Client System Architecture Type Suboption Definition.......3
2.1.1 Client System Architecture Types..........................3
2.2. Client Network Interface Identifier Suboption Definition...3
2.3. Client Machine Identifier Suboption Definition.............4
References.......................................................4
Author Information...............................................4
Full Copyright Statement.........................................5
Introduction
Three DHCP suboptions are being used to uniquely identify booting
client machines and their pre-OS runtime environment so the DHCP
and/or PXE [4] boot server can return the correct OS bootstrap image
(or pre-boot application) name and server to the client.
In the past, this work was done by examining the network MAC address
in the "chaddr" field in the BOOTP/DHCP header and keeping a
database of MAC addresses on the BOOTP/DHCP server. This was deemed
insufficient for large and complex networks for two main reasons.
1) Multiple laptops could end up with the same MAC address if the
NIC was in a shared docking station. 2) Multiple network devices
and MAC addresses could be used by one machine for redundancy or
because of repairs.
Another issue that came up was the machine that could change its
pre-OS runtime environment. This issue caused the creation of
another new suboption to identify the runtime environment so the
correct binary image could be matched up with the booting machine.
1.1. Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [1].
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2. Suboption Definitions
2.1. Client System Architecture Type Suboption Definition
The format of the suboption is:
Code Len 16-bit Type
+----+-----+-----+-----+
| 93 | 2 | n1 | n2 |
+----+-----+-----+-----+
Octets "n1" and "n2" encode a 16-bit architecture type identifier
that describes the pre-boot runtime environment of the client
machine.
2.1.1 Client System Architecture Types
As of the writing of this document the following pre-boot
architecture types have been requested. At present, this list being
maintained by the author.
Type Architecture Name
---- -----------------
0 Intel x86PC
1 NEC/PC98
2 EFI [5] Itanium
3 DEC Alpha
4 Arc x86
5 Intel Lean Client
6 EFI IA32
2.2. Client Network Interface Identifier Suboption Definition
The format of the suboption is:
Code Len Type Major Minor
+----+-----+----+-----+-----+
| 94 | 3 | t | M | m |
+----+-----+----+-----+-----+
Octet "t" encodes a network interface type. For now the only
supported value is 1 for UNDI (Universal Network Device Interface).
Octets "M" and "m" describe the interface revision. To encode the
UNDI revision of 2.11, "M" would set to 2 and "m" would be set to 11
(0x0B).
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2.3. Client Machine Identifier Suboption Definition
The format of the suboption is:
Code Len Type Machine Identifier
+----+-----+----+-----+ . . . +-----+
| 97 | n | t | | . . . | |
+----+-----+----+-----+ . . . +-----+
Octet "t" describes the type of the machine identifier in the
remaining octets in this suboption. 0 (zero) is the only defined
value for this octet at the present time and it describes the
remaining octets as a 16-octet GUID. (One definition of GUID can be
found in Appendix A in the EFI specification [5].)
References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119, BCP 14, March 1997.
[2] Droms, R. "Dynamic Host Configuration Protocol", RFC 2131, March
1997.
[3] Alexander, S. and Droms, R., "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
[4] Henry, M. and Johnston, M., "Preboot Execution Environment (PXE)
Specification", September 1999.
ftp://download.intel.com/labs/manage/wfm/download/pxespec.pdf
[5] Intel Corp., "Extensible Firmware Interface Specification",
December 2002.
http://developer.intel.com/technology/efi/main_specification.htm
Author Information
Michael Johnston
Intel Corporation
MS. JF1-239
2111 NE 25th Ave.
Hillsboro, OR 97124
Phone: +1 503-264-9703
Email: michael.johnston@intel.com
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Full Copyright Statement
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