E6Translate: Bridging IPv4-Only Hosts to IPv6 Internet
draft-ursini-e6translate-00
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Author | Preston Louis Ursini | ||
| Last updated | 2024-11-24 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
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| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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draft-ursini-e6translate-00
Network Working Group P. L. Ursini
Internet-Draft Quad State Internet
Intended status: Informational 24 November 2024
Expires: 28 May 2025
E6Translate: Bridging IPv4-Only Hosts to IPv6 Internet
draft-ursini-e6translate-00
Abstract
E6Translate (E6T) is a protocol designed to address the challenges of
bidirectional communication between IPv4-only hosts and the IPv6
Internet. Leveraging the reserved Class E IPv4 address space
(240.0.0.0/4) as temporary placeholders for IPv6 destinations, E6T
provides a lightweight and scalable mechanism for IPv4-to-IPv6
mapping and vice versa. To enable reverse connectivity, E6T
repurposes a /96 segment of a /64 IPv6 prefix for IPv4-equivalent
mapping, facilitating port forwarding and external access to legacy
devices. This document outlines the design, operation, and practical
applications of E6T, along with considerations for security,
deployment, and protocol standardization.
Note
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
This Internet-Draft will expire on May 26, 2025.
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
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Internet-Drafts are draft documents valid for a maximum of six months
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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 28 May 2025.
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Copyright Notice
Copyright (c) 2024 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/
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
3. E6Translate Protocol Design . . . . . . . . . . . . . . . . . 3
3.1. DNS Masking and Mapping . . . . . . . . . . . . . . . . . 3
3.2. Connection Tracking and Timeouts . . . . . . . . . . . . 3
3.3. Router-Level Translation . . . . . . . . . . . . . . . . 3
3.4. IPv6-to-IPv4 Reverse Mapping and Port Forwarding . . . . 4
4. Protocol Workflow . . . . . . . . . . . . . . . . . . . . . . 4
5. Practical Benefits for Network Administrators . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
8. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 5
9. Normative References . . . . . . . . . . . . . . . . . . . . 5
10. Informative References . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
The transition to IPv6 has been slow due to the persistence of legacy
IPv4-only devices in many networks. While solutions like NAT64 and
DNS64 exist, they often require significant configuration expertise
and specialized infrastructure. Many small organizations and home
networks lack the technical expertise to deploy these solutions
effectively.
E6Translate (E6T) is a protocol aimed at bridging this gap. By using
the reserved Class E IPv4 space (240.0.0.0/4) for temporary mapping
and providing reverse connectivity via IPv6 port-forwarding, E6T
simplifies cross-protocol communication. This solution is
particularly well-suited for environments with mixed IPv4 and IPv6
traffic, allowing network administrators to maintain functionality
without upgrading legacy devices.
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2. Problem Statement
The transition to IPv6 is hampered by:
* Legacy IPv4 Devices: Many existing devices do not support IPv6
natively, creating connectivity challenges in IPv6-only
environments.
* Complex Transition Mechanisms: Current solutions like NAT64
require significant configuration, making them impractical for
small-scale deployments.
* IPv6 Connectivity Gaps: IPv4-only devices cannot access IPv6-only
resources, limiting interoperability.
E6T addresses these challenges with a lightweight, bidirectional
mapping mechanism.
3. E6Translate Protocol Design
3.1. DNS Masking and Mapping
E6T-aware DNS servers intercept DNS queries from IPv4-only hosts for
IPv6 destinations and respond with temporary Class E IPv4 addresses
mapped to the requested IPv6 resource.
* Dynamic Address Allocation: Temporary mappings are dynamically
created and stored in a connection tracking table.
* Seamless Resolution: IPv4-only hosts remain unaware of the
mapping, receiving valid IPv4 responses.
3.2. Connection Tracking and Timeouts
The E6T router manages a connection tracking table:
* Mapping Expiration: Entries expire after a timeout to conserve
resources.
* Session Persistence: Active sessions retain their mappings for the
duration of communication. Connections are tracked in a similar
fashion to IPv4 NAT.
3.3. Router-Level Translation
E6T routers perform bidirectional translation:
* IPv4-to-IPv6: Outbound IPv4 packets are translated to IPv6.
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* IPv6-to-IPv4: Inbound IPv6 packets are translated back to IPv4.
3.4. IPv6-to-IPv4 Reverse Mapping and Port Forwarding
Reverse mapping assigns each IPv4 address a corresponding IPv6
address within a reserved /96 IPv6 prefix:
* Example Mapping:
* IPv4 Address: 192.0.2.0
* IPv6 Address: 2001:db8::c0a8:0164
Port forwarding routes traffic from IPv6 clients to IPv4 devices.
4. Protocol Workflow
* DNS Query: An IPv4-only host queries an E6T-aware DNS server for
an IPv6 resource.
* Address Allocation: The DNS server allocates a temporary Class E
IPv4 address.
* Outbound Traffic: The host sends packets to the temporary IPv4
address, which the E6T router translates to IPv6.
* Reverse Mapping: External IPv6 clients access IPv4 devices via
port forwarding.
5. Practical Benefits for Network Administrators
* Simplified Transition: Minimal configuration requirements reduce
administrative overhead.
* Legacy Device Support: Enables IPv6 connectivity without upgrading
hardware.
* Scalability: Efficient resource allocation prevents address
exhaustion.
6. Security Considerations
* Spoofing Mitigation: Validate all incoming and outgoing packets to
prevent mapping misuse.
* State Exhaustion: Rate-limiting mechanisms prevent denial-of-
service attacks.
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* Connection Tracking Security: Ensure proper isolation between
mapping sessions.
7. IANA Considerations
This proposal recommends reassigning the reserved Class E IPv4
address space (240.0.0.0/4) for E6Translate mappings. Additionally,
a standardized /96 IPv6 prefix allocation is required for reverse
mapping.
8. Conclusion
E6Translate provides a scalable, lightweight solution for bridging
IPv4-only devices to the IPv6 Internet. Its design minimizes
complexity while offering practical benefits for network
administrators managing mixed-protocol environments.
9. Normative References
[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., de Groot, G.,
and E. Lear, "Address Allocation for Private Internets",
February 1996, <https://www.rfc-editor.org/info/rfc1918>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", December 1998,
<https://www.rfc-editor.org/info/rfc2460>.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
Addresses", October 2005,
<https://www.rfc-editor.org/info/rfc4193>.
[RFC5735] Lear, E., "Special Use IPv4 Addresses", January 2010,
<https://www.rfc-editor.org/info/rfc5735>.
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
Li, "IPv6 Addressing of IPv4/IPv6 Translators", October
2010, <https://www.rfc-editor.org/info/rfc6052>.
[RFC7346] DeLong, O. and L. Howard, "IPv6 Multihoming without
Network Prefix Translation", August 2014,
<https://www.rfc-editor.org/info/rfc7346>.
10. Informative References
[RFC6182] Ford, A., Raiciu, C., and M. Handley, "Architectural
Guidelines for Multipath TCP Development", March 2011,
<https://www.rfc-editor.org/info/rfc6182>.
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[RFC2993] Durham, I. and B. Carpenter, "Architectural Implications
of NAT", November 2000,
<https://www.rfc-editor.org/info/rfc2993>.
[RFC8305] Schinazi, D. and T. Pauly, "Happy Eyeballs Version 2:
Better Connectivity Using Concurrency", December 2018,
<https://www.rfc-editor.org/info/rfc8305>.
Author's Address
Preston Louis Ursini
Quad State Internet
1212 Helen Street
Paducah, KY 42001
United States
Phone: +1 833-701-7823
Email: preston@quadstateinternet.net
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