MAC Address as String
draft-sam-mac-address-as-string-00

NETMOD Working Group                                        S. Mansfield
Internet-Draft                                                  Ericsson
Intended status: Informational                              2 March 2026
Expires: 3 September 2026

                         MAC Address as String
                   draft-sam-mac-address-as-string-00

Abstract

   IETF and IEEE 802.1 have different patterns for mac addresses in
   their respective YANG types modules.  Therefore equivalent mac
   addresses may or may not match if a mac-address that uses the IETF
   datatype is compared to a mac-address that uses the IEEE datatype
   (and vise-versa).

Discussion Venues

   This note is to be removed before publishing as an RFC.

   Source for this draft and an issue tracker can be found at
   https://github.com/samans/draft-sam-mac-address-as-string.

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   This Internet-Draft will expire on 3 September 2026.

Copyright Notice

   Copyright (c) 2026 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Detail  . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  IETF Format . . . . . . . . . . . . . . . . . . . . . . .   3
     3.2.  IEEE Format . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Options . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   7.  Informative References  . . . . . . . . . . . . . . . . . . .   4
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   MAC Address Formats in the IETF and IEEE YANG modules are different.

2.  Problem Statement

   The IETF YANG module [RFC9911] and IEEE YANG [IEEE-802-1Qcw] module
   use a datatype of String to store MAC Addresses.  The issue is that
   the IETF and IEEE use different patterns and have different canonical
   forms, which leads to a situation where equivalent MAC Addresses will
   not match.

   This internet-draft is meant to document the issue, raise awareness,
   and identify potential solutions.

   For example, the following MAC Address is in IETF Canonical Format

      90-10-00-01-02-AA

   For example, the following MAC Address is in IEEE Canonical Format

      90:10:00:01:02:aa

   The MAC Address are equivalent, but will not match if used in an
   XPATH, or as a key, or any string comparison.

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   There are several potential trouble spots in published IETF YANG
   modules.

3.  Detail

3.1.  IETF Format

   The IETF Format (from ietf-yang-types@2013-07-15.yang) used in the
   mac-address typedef is found below.

   typedef mac-address {
    type string {
      pattern '[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}';
    }
    description
     "The mac-address type represents an IEEE 802 MAC address.
      The canonical representation uses lowercase characters.

      In the value set and its semantics, this type is equivalent
      to the MacAddress textual convention of the SMIv2.";
    reference
     "IEEE 802: IEEE Standard for Local and Metropolitan Area
                Networks: Overview and Architecture
      RFC 2579: Textual Conventions for SMIv2";
   }

3.2.  IEEE Format

   The IEEE Format used in the mac-address typedef is found below.

   typedef mac-address {
    type string {
      pattern "[0-9a-fA-F]{2}(-[0-9a-fA-F]{2}){5}";
    }
    description
      "The mac-address type represents a MAC address in the canonical
       format and hexadecimal format specified by IEEE Std 802. The
       hexadecimal representation uses uppercase characters.";
    reference
      "3.1, 8.1 of IEEE Std 802";
   }

4.  Options

   *  Create a new mac-address type and deprecate the mac-address types
      in IETF and IEEE types files.

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   *  Modify the mac-address patterns in both IETF and IEEE to be
      inclusive of everything, and fix the descriptions to warn the
      implementers about the issue with equivalence.

   *  Add something to the YANG language that will provide a way to
      indicate an "equivalence" pattern.

   *  Do what SMNP did, abandon strings and store the MAC Address as 6
      octets and provide the ability to use a display hint style
      facility.

   *  Do Nothing

   *  Some other brilliant solution?

5.  Security Considerations

   TODO Security

6.  IANA Considerations

   This document has no IANA actions.

7.  Informative References

   [IEEE-802-1Qcw]
              "IEEE Standard for Local and Metropolitan Area Networks--
              Bridges and Bridged Networks Amendment 36: YANG Data
              Models for Scheduled Traffic, Frame Preemption, and
              Per‐Stream Filtering and Policing", 17 November 2023,
              <https://doi.org/10.1109/IEEESTD.2023.10317806>.

   [RFC9911]  Schönwälder, J., Ed., "Common YANG Data Types", RFC 9911,
              DOI 10.17487/RFC9911, December 2025,
              <https://www.rfc-editor.org/rfc/rfc9911>.

Acknowledgments

   TODO acknowledge.

Author's Address

   Scott Mansfield
   Ericsson
   Email: scott.mansfield@ericsson.com

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