draft-ietf-dhc-pxe-options-00.txt   draft-ietf-dhc-pxe-options-01.txt 
INTERNET-DRAFT M. Johnston Dynamic Host Configuration Working M. Johnston
draft-ietf-dhc-pxe-options-00.txt Intel Corporation Group Intel Corporation
Expires: February 2004 28 August 2003
DHCP Preboot eXecution Environment (PXE) Suboptions Expires: July 22, 2005
<draft-ietf-dhc-pxe-options-00.txt>
DHCP Preboot eXecution Environment (PXE) Options
draft-ietf-dhc-pxe-options-01.txt
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Abstract Abstract
Define DHCP suboptions being used by PXE and EFI clients. Define DHCP options being used by PXE and EFI clients.
Requirements Language
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 [RFC2119].
Table of Contents Table of Contents
Status of this Memo..............................................1 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
Copyright Notice.................................................1 2. Revision history . . . . . . . . . . . . . . . . . . . . . . . 3
Abstract.........................................................1 3. Option Definitions . . . . . . . . . . . . . . . . . . . . . . 3
Table of Contents................................................2 3.1 Client System Architecture Type Option Definition . . . . 3
Introduction.....................................................2 3.2 Client Network Interface Identifier Option Definition . . 4
1.1. Conventions................................................2 3.3 Client Machine Identifier Option Definition . . . . . . . 5
2. Suboption Definitions........................................3 3.4 Site Specific Options Being Requested By PXE Client . . . 5
2.1. Client System Architecture Type Suboption Definition.......3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
2.1.1 Client System Architecture Types..........................3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6
2.2. Client Network Interface Identifier Suboption Definition...3 6. Normative References . . . . . . . . . . . . . . . . . . . . . 6
2.3. Client Machine Identifier Suboption Definition.............4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 6
References.......................................................4 Intellectual Property and Copyright Statements . . . . . . . . 7
Author Information...............................................4
Full Copyright Statement.........................................5
Introduction 1. Introduction
Three DHCP suboptions are being used to uniquely identify booting These DHCP options [RFC2131] are being widely used by PXE compliant
client machines and their pre-OS runtime environment so the DHCP clients to uniquely identify booting client machines themselves and
and/or PXE [4] boot server can return the correct OS bootstrap image their pre-OS runtime environment so the DHCP and/or PXE boot server
(or pre-boot application) name and server to the client. 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 option to identify the runtime
environment so the correct binary image could be matched up with the
booting machine. These options are defined in the PXE [pxe] and EFI
[efi] specifications and are being documented in this draft for
completeness within the IETF. Comments about this Internet Draft
should be sent to the dhcwg@ietf.org mailing list.
In the past, this work was done by examining the network MAC address 2. Revision history
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 Revision 00 to Revision 01
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 o Changed all occurrences of "suboption" to "option".
o Re-worded first sentence of Introduction to clarify that these
options are in wide use by PXE clients.
o Clarified external document references.
o Added description of site specific options 128 through 135.
o Added IANA Considerations and Security Considerations sections.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 3. Option Definitions
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [1].
2. Suboption Definitions There are three DHCP options [RFC2132]defined for use by PXE clients.
2.1. Client System Architecture Type Suboption Definition 3.1 Client System Architecture Type Option Definition
The format of the suboption is: The format of the option is:
Code Len 16-bit Type Code Len 16-bit Type
+----+-----+-----+-----+ +----+---+------+------+
| 93 | 2 | n1 | n2 | | 93 | n | 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 Octet "n" MUST be an even number greater than zero. Clients that
support more than one architecture type MAY include a list of these
types in their initial DHCP and PXE boot server packets. The list of
supported architecture types MAY be reduced in any packet exchange
between the client and server(s). Octets "n1" and "n2" encode a
16-bit architecture type identifier that describes the pre-boot
runtime environment(s) of the client machine.
As of the writing of this document the following pre-boot As of the writing of this document the following pre-boot
architecture types have been requested. At present, this list being architecture types have been requested.
maintained by the author.
Type Architecture Name Type Architecture Name
---- ----------------- ---- -----------------
0 Intel x86PC 0 Intel x86PC
1 NEC/PC98 1 NEC/PC98
2 EFI [5] Itanium 2 EFI Itanium
3 DEC Alpha 3 DEC Alpha
4 Arc x86 4 Arc x86
5 Intel Lean Client 5 Intel Lean Client
6 EFI IA32 6 EFI IA32
2.2. Client Network Interface Identifier Suboption Definition This option must be present in all DHCP and PXE packets sent by PXE
compliant clients and servers.
The format of the suboption is: 3.2 Client Network Interface Identifier Option Definition
The format of the option is:
Code Len Type Major Minor Code Len Type Major Minor
+----+-----+----+-----+-----+ +----+-----+----+-----+-----+
| 94 | 3 | t | M | m | | 94 | 3 | t | M | m |
+----+-----+----+-----+-----+ +----+-----+----+-----+-----+
Octet "t" encodes a network interface type. For now the only Octet "t" encodes a network interface type. For now the only
supported value is 1 for UNDI (Universal Network Device Interface). supported value is 1 for UNDI (Universal Network Device Interface).
Octets "M" and "m" describe the interface revision. To encode the 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 UNDI revision of 2.11, "M" would set to 2 and "m" would be set to 11
(0x0B). (0x0B).
2.3. Client Machine Identifier Suboption Definition Revision Description
-------- -----------
< 2.00 LANDesk service agent boot ROMs. No PXE APIs.
The format of the suboption is: 2.00 First generation PXE boot ROMs. (PXENV+) [pxe]
2.01 Second generation PXE boot ROMs. (!PXE) [pxe]
3.00 32/64-bit UNDI specification. (Alpha) [efi]
EFI boot services driver only. No EFI runtime support.
3.10 32/64-bit UNDI specification. (Beta) [efi]
First generation EFI runtime driver support.
3.20 32/64-bit UNDI specification. (Release) [efi]
Second generation EFI runtime driver support.
This option must be present in all DHCP and PXE packets sent by PXE
compliant clients and servers.
3.3 Client Machine Identifier Option Definition
The format of the option is:
Code Len Type Machine Identifier Code Len Type Machine Identifier
+----+-----+----+-----+ . . . +-----+ +----+-----+----+-----+ . . . +-----+
| 97 | n | t | | . . . | | | 97 | n | t | | . . . | |
+----+-----+----+-----+ . . . +-----+ +----+-----+----+-----+ . . . +-----+
Octet "t" describes the type of the machine identifier in the Octet "t" describes the type of the machine identifier in the
remaining octets in this suboption. 0 (zero) is the only defined remaining octets in this option. 0 (zero) is the only defined value
value for this octet at the present time and it describes the for this octet at the present time and it describes the remaining
remaining octets as a 16-octet GUID. (One definition of GUID can be octets as a 16-octet GUID. Octet "n" is 17 for type 0. (One
found in Appendix A in the EFI specification [5].) definition of GUID can be found in Appendix A in the EFI
specification [efi].)
References This option must be present in all DHCP and PXE packets sent by PXE
compliant clients and servers.
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement 3.4 Site Specific Options Being Requested By PXE Client
Levels", RFC 2119, BCP 14, March 1997.
[2] Droms, R. "Dynamic Host Configuration Protocol", RFC 2131, March All compliant PXE clients MUST include a request for DHCP options 128
1997. through 135 in all DHCP and PXE packets. The format and contents of
these options are NOT defined by the PXE specification. These
options MAY be present in the DHCP and PXE boot server replies and
are meant for use by the downloaded network bootstrap programs.
These options are NOT used by the PXE boot ROMs.
[3] Alexander, S. and Droms, R., "DHCP Options and BOOTP Vendor 4. IANA Considerations
This document defines two new name spaces associated with PXE
compliant client machines: Client System Architecture Type and Client
Network Interface Identifier. IANA is requested to manage a registry
of values for these new name spaces, which are described in sections
2.1 and 2.2.
5. Security Considerations
This document in and by itself provides no security, nor does it
impact existing security.
6 Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC
2131, March 1997.
[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997. Extensions", RFC 2132, March 1997.
[4] Henry, M. and Johnston, M., "Preboot Execution Environment (PXE) [efi] Intel Corp., "Extensible Firmware Interface
Specification", September 1999. Specification", December 2002.
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 http://developer.intel.com/technology/efi/main_specification.htm
Author Information [pxe] Henry, M. and M. Johnston, "Preboot Execution Environment
(PXE) Specification", September 1999.
ftp://download.intel.com/labs/manage/wfm/download/pxespec.pdf
Author's Address
Michael Johnston Michael Johnston
Intel Corporation Intel Corporation
MS. JF1-239 MS. JF1-239 2111 NE 25th Ave.
2111 NE 25th Ave.
Hillsboro, OR 97124 Hillsboro, OR 97124
USA
Phone: +1 503-264-9703 Phone: +1 503-264-9703
Email: michael.johnston@intel.com EMail: michael.johnston@intel.com
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