Host Address Availability Recommendations
RFC 7934
Document | Type |
RFC - Best Current Practice
(July 2016; Errata)
Also known as BCP 204
|
|
---|---|---|---|
Authors | Lorenzo Colitti , Vinton Cerf , Stuart Cheshire , David Schinazi | ||
Last updated | 2016-09-20 | ||
Replaces | draft-colitti-v6ops-host-addr-availability | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Fred Baker | ||
Shepherd write-up | Show (last changed 2016-02-15) | ||
IESG | IESG state | RFC 7934 (Best Current Practice) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Joel Jaeggli | ||
Send notices to | draft-ietf-v6ops-host-addr-availability.all@tools.ietf.org | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) L. Colitti Request for Comments: 7934 V. Cerf BCP: 204 Google Category: Best Current Practice S. Cheshire ISSN: 2070-1721 D. Schinazi Apple Inc. July 2016 Host Address Availability Recommendations Abstract This document recommends that networks provide general-purpose end hosts with multiple global IPv6 addresses when they attach, and it describes the benefits of and the options for doing so. Status of This Memo This memo documents an Internet Best Current Practice. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on BCPs is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7934. Copyright Notice Copyright (c) 2016 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. Colitti, et al. Best Current Practice [Page 1] RFC 7934 Host Address Availability Recommendations July 2016 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Common IPv6 Deployment Model . . . . . . . . . . . . . . . . 3 3. Benefits of Providing Multiple Addresses . . . . . . . . . . 3 4. Problems with Restricting the Number of Addresses per Host . 4 5. Overcoming Limits Using Network Address Translation . . . . . 5 6. Options for Providing More Than One Address . . . . . . . . . 6 7. Number of Addresses Required . . . . . . . . . . . . . . . . 8 8. Recommendations . . . . . . . . . . . . . . . . . . . . . . . 8 9. Operational Considerations . . . . . . . . . . . . . . . . . 9 9.1. Host Tracking . . . . . . . . . . . . . . . . . . . . . . 9 9.2. Address Space Management . . . . . . . . . . . . . . . . 10 9.3. Addressing Link-Layer Scalability Issues via IP Routing . 10 10. Security Considerations . . . . . . . . . . . . . . . . . . . 11 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 11.1. Normative References . . . . . . . . . . . . . . . . . . 11 11.2. Informative References . . . . . . . . . . . . . . . . . 11 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 1. Introduction In most aspects, the IPv6 protocol is very similar to IPv4. This similarity can create a tendency to think of IPv6 as 128-bit IPv4, and thus lead network designers and operators to apply identical configurations and operational practices to both. This is generally a good thing because it eases the transition to IPv6 and the operation of dual-stack networks. However, in some design and operational areas, it can lead to carrying over IPv4 practices that are limiting or not appropriate in IPv6 due to differences between the protocols. One such area is IP addressing, particularly IP addressing of hosts. This is substantially different because unlike IPv4 addresses, IPv6 addresses are not a scarce resource. In IPv6, a single link provides over four billion times more address space than the whole IPv4 Internet [RFC7421]. Thus, unlike IPv4, IPv6 networks are not forced by address scarcity concerns to provide only one address per host. Furthermore, providing multiple addresses has many benefits, including application functionality and simplicity, privacy, and flexibility to accommodate future applications. Another significant benefit is the ability to provide Internet access without the use of Network Address Translation (NAT). Providing only one IPv6 address per host negates these benefits.Show full document text