Network Working Group B. Liu
Internet Draft S. Jiang
Intended status: Best Current Practice Huawei Technologies
Expires: August 28, 2013 C. Byrne
T-Mobile USA
February 25, 2013
Guidance of Using Unique Local Addresses
draft-liu-v6ops-ula-usage-analysis-05.txt
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Abstract
This document provides guidance of how to use ULA. It analyzes ULA
usage scenarios and recommends use cases where ULA address may be
beneficially used.
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Internet-Draft draft-liu-v6ops-ula-usage-analysis-05 February 2013
Table of Contents
1. Introduction ................................................. 2
2. ULA usage analysis ........................................... 3
2.1. The features of ULA ..................................... 3
2.1.1. Self-assigned ...................................... 3
2.1.2. Globally unique .................................... 3
2.1.3. Independent address space .......................... 3
2.1.4. Well known prefix .................................. 4
2.1.5. Stable or Temporary Prefix ......................... 4
2.2. Enumeration of ULA use scenarios ........................ 4
2.2.1. Isolated network ................................... 4
2.2.2. Connected network .................................. 5
2.2.2.1. ULA-only Deployment ........................... 5
2.2.2.2. ULA along with GUA ............................ 6
3. Recommended ULA Use Cases .................................... 6
3.1. Used in Isolated Networks ............................... 6
3.2. ULA along with GUA ...................................... 6
3.3. Special Use Cases ....................................... 7
3.3.1. Special routing .................................... 7
3.3.2. Used as NAT64 prefix ............................... 7
3.3.3. Used as identifier ................................. 8
4. Security Considerations ...................................... 8
5. IANA Considerations .......................................... 8
6. Conclusions .................................................. 9
7. References ................................................... 9
7.1. Normative References .................................... 9
7.2. Informative References .................................. 9
8. Acknowledgments ............................................. 10
1. Introduction
Unique Local Addresses (ULAs) are defined in [RFC4193] as provider-
independent prefixes that can be used on isolated networks, internal
networks, and VPNs. Although ULAs may be treated like global scope by
applications, normally they are not used on the publicly routable
internet.
However, the ULAs haven't been widely used since IPv6 hasn't been
widely deployed yet.
The use of ULA addresses in various types of networks has been confused
for network operators. Some network operators believe ULAs are not
useful at all while other network operators run their entire networks on
ULA address space. This document attempts to clarify the advantages and
disadvantages of ULAs and how they can be most appropriately used.
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