RFC 2469 (rfc2469) - Page 1 of 5
A Caution On The Canonical Ordering Of Link-Layer Addresses
Alternative Format: Original Text Document
Network Working Group T. Narten
Request for Comments: 2469 C. Burton
Category: Informational IBM
December 1998
A Caution On The Canonical Ordering Of Link-Layer Addresses
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.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
Protocols such as ARP and Neighbor Discovery have data fields that
contain link-layer addresses. In order to interoperate properly, a
sender setting such a field must insure that the receiver extracts
those bits and interprets them correctly. In most cases, such fields
must be in "canonical form". Unfortunately, not all LAN adaptors are
consistent in their use of canonical form, and implementations may
need to explicitly bit swap individual bytes in order to obtain the
correct format. This document provides information to implementors
to help them avoid the pitfall of using non-canonical forms when
canonical forms are required.
Table of Contents
1. Introduction............................................. 2
2. Canonical Form........................................... 2
3. Implementors Beware: Potential Trouble Spots............. 3
3.1. Neighbor Discovery in IPv6.......................... 3
3.2. IPv4 and ARP........................................ 3
4. Security Considerations.................................. 3
5. References............................................... 4
6. Authors' Addresses....................................... 4
7. Full Copyright Statement................................. 5
Narten & Burton Informational