Considerations For Using Unique Local Addresses
draft-ietf-v6ops-ula-usage-considerations-02

Document Type Active Internet-Draft (v6ops WG)
Last updated 2017-03-13
Replaces draft-ietf-v6ops-ula-usage-recommendations
Stream IETF
Intended RFC status (None)
Formats plain text xml pdf html bibtex
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state I-D Exists
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to (None)
Internet Engineering Task Force                                   B. Liu
Internet-Draft                                                  S. Jiang
Intended status: Informational                       Huawei Technologies
Expires: September 14, 2017                               March 13, 2017

            Considerations For Using Unique Local Addresses
              draft-ietf-v6ops-ula-usage-considerations-02

Abstract

   This document provides considerations for using IPv6 Unique Local
   Addresses (ULAs).  Based on an analysis of different ULA usage
   scenarios, this document identifies use cases where ULA addresses are
   helpful as well as potential problems caused by using them.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 14, 2017.

Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Liu & Jiang            Expires September 14, 2017               [Page 1]
Internet-Draft                  ULA Usage                     March 2017

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  General Considerations For Using ULAs . . . . . . . . . . . .   3
     3.1.  Do Not Treat ULA Equal to RFC1918 . . . . . . . . . . . .   3
     3.2.  Using ULAs in a Limited Scope . . . . . . . . . . . . . .   4
   4.  Analysis and Operational Considerations for Scenarios Using
       ULAs  . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  ULA-only in Isolated Networks . . . . . . . . . . . . . .   4
     4.2.  ULA+PA in Connected Networks  . . . . . . . . . . . . . .   5
     4.3.  ULA-Only in Connected Networks  . . . . . . . . . . . . .   7
     4.4.  Some Specific Use Cases . . . . . . . . . . . . . . . . .   8
       4.4.1.  Special Routing . . . . . . . . . . . . . . . . . . .   8
       4.4.2.  Used as Identifier  . . . . . . . . . . . . . . . . .   8
     4.5.  IPv4 Co-existence Considerations  . . . . . . . . . . . .   9
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   Unique Local Addresses (ULA) is defined in [RFC4193], and it is an
   alternative to site-local address (deprecated in [RFC3879]).  ULAs
   have the following features:

   -  Automatically Generated

      ULA prefixes can be automatically generated using the algorithms
      described in [RFC4193].  This feature allows automatic prefix
      allocation.  Thus one can get a network working immediately
      without applying for prefix(es) from an RIR/LIR (Regional Internet
      Registry/Local Internet Registry).

   -  Globally Unique

      ULAs are defined as a global scope address space.  However, they
      are not intended to be used globally on the public Internet; in
      contrast, they are mostly used locally, for example, in isolated
      networks, internal networks, or VPNs.

      ULAs are intended to have an extremely low probability of
      collision.  The randomization of 40 bits in a ULA prefix is
      considered sufficient enough to ensure a high degree of uniqueness
Show full document text