Dynamic Host Configuration Protocol Options Used by PXELINUX
RFC 5071
| Document | Type | RFC - Informational (December 2007; No errata) | |
|---|---|---|---|
| Author | David Hankins | ||
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 5071 (Informational) | |
| Action Holders |
(None)
|
||
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Jari Arkko | ||
| Send notices to | (None) | ||
Network Working Group D. Hankins
Request for Comments: 5071 ISC
Category: Informational December 2007
Dynamic Host Configuration Protocol Options Used by PXELINUX
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Abstract
This document describes the use by PXELINUX of some DHCP Option Codes
numbering from 208-211.
Hankins Informational [Page 1]
RFC 5071 PXELINUX Options December 2007
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. MAGIC Option . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Description . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Packet Format . . . . . . . . . . . . . . . . . . . . . . 5
3.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 5
3.4. Response to RFC 3942 . . . . . . . . . . . . . . . . . . . 5
4. Configuration File Option . . . . . . . . . . . . . . . . . . 5
4.1. Description . . . . . . . . . . . . . . . . . . . . . . . 5
4.2. Packet Format . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 6
4.4. Response to RFC 3942 . . . . . . . . . . . . . . . . . . . 6
4.5. Client and Server Behaviour . . . . . . . . . . . . . . . 6
5. Path Prefix Option . . . . . . . . . . . . . . . . . . . . . . 7
5.1. Description . . . . . . . . . . . . . . . . . . . . . . . 7
5.2. Packet Format . . . . . . . . . . . . . . . . . . . . . . 7
5.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 7
5.4. Response to RFC 3942 . . . . . . . . . . . . . . . . . . . 8
5.5. Client and Server Behaviour . . . . . . . . . . . . . . . 8
6. Reboot Time Option . . . . . . . . . . . . . . . . . . . . . . 9
6.1. Description . . . . . . . . . . . . . . . . . . . . . . . 9
6.2. Packet Format . . . . . . . . . . . . . . . . . . . . . . 9
6.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 10
6.4. Response to RFC 3942 . . . . . . . . . . . . . . . . . . . 10
6.5. Client and Server Behaviour . . . . . . . . . . . . . . . 10
7. Specification Conformance . . . . . . . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
11.1. Normative References . . . . . . . . . . . . . . . . . . . 12
11.2. Informative References . . . . . . . . . . . . . . . . . . 12
Hankins Informational [Page 2]
RFC 5071 PXELINUX Options December 2007
1. Introduction
PXE, the Preboot eXecution Environment, is a first-stage network
bootstrap agent. PXE is loaded out of firmware on the client host,
and performs DHCP [3] queries to obtain an IP address.
Once on the network, it loads a second-stage bootstrap agent as
configured by DHCP header and option contents.
PXELINUX is one such second-stage bootstrap agent. Once PXE has
passed execution to it, PXELINUX seeks its configuration from a cache
of DHCP options supplied to the PXE first-stage agent, and then takes
action based upon those options.
Most frequently, this implies loading via Trivial File Transfer
Protocol (TFTP) [6] one or more images that are decompressed into
memory, then executed to pass execution to the final Host Operating
System.
PXELINUX uses DHCP options 208-211 to govern parts of this bootstrap
process, but these options are not requested by the PXE DHCP client
at the time it acquires its lease. At that time, the PXE bootloader
has no knowledge that PXELINUX is going to be in use, and even so,
would have no way to know what option(s) PXELINUX might digest.
Local installations that serve this PXELINUX image to its clients
must also configure their DHCP servers to provide these options even
though they are not on the DHCP Parameter Request List [4].
These options are:
o "MAGIC" - 208 - An option whose presence and content verifies to
the PXELINUX bootloader that the options numbered 209-211 are for
the purpose as described herein.
o "ConfigFile" - 209 - Configures the path/filename component of the
configuration file's location, which this bootloader should use to
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