v6ops J. Palet Martinez Internet-Draft Consulintel, S.L. Intended status: Informational October 16, 2017 Expires: April 19, 2018 IPv6-only Terminology Definition draft-palet-v6ops-ipv6-only-02 Abstract This document defines the terminology regarding the usage of expressions such as "IPv6-only", in order to avoid confusions when using them in IETF and other documents, in reference to what is the actual functionalities being used (not the actual protocol support). 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 https://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 April 19, 2018. 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 (https://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. Palet Martinez Expires April 19, 2018 [Page 1] Internet-Draft IPv6-only Definition October 2017 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Context . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Definition of IPv6-only . . . . . . . . . . . . . . . . . . . 3 4. Dual-stack . . . . . . . . . . . . . . . . . . . . . . . . . 3 5. Native dual-stack . . . . . . . . . . . . . . . . . . . . . . 3 6. IPv6-only network . . . . . . . . . . . . . . . . . . . . . . 3 7. IPv6-only WAN/access . . . . . . . . . . . . . . . . . . . . 4 8. IPv6-only LAN . . . . . . . . . . . . . . . . . . . . . . . . 4 9. IPv6-only host/router . . . . . . . . . . . . . . . . . . . . 4 10. Transitional IPv6 host/router . . . . . . . . . . . . . . . . 4 11. Other cases . . . . . . . . . . . . . . . . . . . . . . . . . 4 12. Security Considerations . . . . . . . . . . . . . . . . . . . 4 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction Due to the nature of the Internet and the different types of users, parts of a network, providers, flows, etc., there is not a single and easy way to categorically say something such as "IPv6-only". The goal of this document is to depict this situation and agree in a common language to be used for IETF and other documents, in order to facilitate ourselves and future readers, the correct understanding of what we are talking about. Note that all the references in this document are regarding the actual usage of IPv4/IPv6, not the support of those protocols by nodes. For example, a device or access network may support both IPv4 and IPv6, however actually is only "natively" forwarding IPv6. 2. Context The transition from IPv4 to IPv6 is not something that can be done, in the large majority of the cases, overnight and in a single step. Consequently, in general, we are unable to talk about a whole network having a "single and uniform" status regarding IPv6, at least not in the early deployment stages of an operator network. Even if ossible, it is not frequent to deploy new IPv6 networks which have no IPv4 connectivity at all, because at the current phase of the universal goal of the IPv6 deployment, almost every network still need to provide some kind of "access" to IPv4 sites. It is not feasible for most of the operators to tell their customers "I can provide you IPv6 service, but you will not be able to access all Palet Martinez Expires April 19, 2018 [Page 2] Internet-Draft IPv6-only Definition October 2017 Internet contents and apps, because some of them still don't support IPv6, so you will miss every content that it is IPv4-only". Some networks may have IPv6-only support for specific purposes. For example, a DOCSIS provider may have decided that is worth the effort to get rid of IPv4 for the management network of the cable-modems. Or a network that provides connectivity only to IoT devices, may be IPv6-only. However, the "end-networks", in general, need to continue supporting IPv4, as there are many devices or apps, in both corporate and end- user networks (smartTV, IP cameras, etc.), which are IPv4-only and it is not feasible to update or replace them. In IPv6-only access networks, IPv4 support maybe provided by mechanisms that allow "IPv4-as-a-service" (for example by means of encapsulation and/or translation on top of IPv6). 3. Definition of IPv6-only Consequently, considering the context described in the section above, if we want to be precise and avoid confusing others, we can not use the terminology "IPv6-only" in a generic way, and we need to define what part of the network we are referring to. From that perspective, we define the "IPv6-only" status in a given part(s) of a network, depending on if there is actual native forwarding of IPv4, so IPv4 is not configured neither managed. 4. Dual-stack This can be applied to a host, router, link, network, etc. It means that both, IPv4 and IPv6 are reachable, without specifying how. 5. Native dual-stack This can be applied to a host, router, link, network, etc. It means that both, IPv4 and IPv6 are configured/used natively (without the need of transition mechanisms). 6. IPv6-only network IPv6-only can be used only if, a complete network, end-to-end, is actually not natively forwarding IPv4, which will mean that no-IPv4 addresses are configured, neither used for management, neither the network is providing transition/translation support, neither there is IPv4 transit/peering. Palet Martinez Expires April 19, 2018 [Page 3] Internet-Draft IPv6-only Definition October 2017 This is the end of the road of the IPv4-to-IPv6 transition, however we aren't there yet, in general at the time of writing this document, unless we are referring to special or disconnected (from IPv4) networks. 7. IPv6-only WAN/access IPv6-only WAN or access can be used only if the WAN or access network isn't actually natively forwarding IPv4. 8. IPv6-only LAN IPv6-only LAN(s) can be used only if the LAN(s), isn't actually natively transporting IPv4. 9. IPv6-only host/router IPv6-only host/router can be used only if the host/router, isn't actually using/forwarding IPv4, so IPv4 is unconfigured and/or disabled on all the interfaces. 10. Transitional IPv6 host/router Transitional dual-stack host/router is a dual-stack host/router with IPv6-only WAN where IPv4 service support is provided by means of transition mechanism, "as-a-service". 11. Other cases Similar other cases or parts of the network can be considered as IPv6-only if there is no actual native forwarding of IPv4 and in that case, after "IPv6-only" some word/short text pointing to the specific case or part of the network needs to be used. 12. Security Considerations This document does not have any specific security considerations. 13. IANA Considerations This document does not have any IANA considerations. 14. Acknowledgements The author would like to acknowledge the inputs from Tim Chown, Noah Maina and Lee Howard. Palet Martinez Expires April 19, 2018 [Page 4] Internet-Draft IPv6-only Definition October 2017 Author's Address Jordi Palet Martinez Consulintel, S.L. Molino de la Navata, 75 La Navata - Galapagar, Madrid 28420 Spain Email: jordi.palet@consulintel.es URI: http://www.consulintel.es/ Palet Martinez Expires April 19, 2018 [Page 5]