Internet DRAFT - draft-wang-v6ops-xlat-prefix-discovery
draft-wang-v6ops-xlat-prefix-discovery
DHC Working Group W. Wang
Internet-Draft L. Zhang
Intended status: Standards Track X. Que
Expires: March 19, 2015 BUPT University
L. Li
Tsinghua University
Y. Wang
BUPT University
September 15, 2014
Discovery of the IPv6 Prefix in 464XLAT
draft-wang-v6ops-xlat-prefix-discovery-00
Abstract
The 464XLAT[RFC6877] provides a solution with limited IPv4
connectivity across an IPv6-only network. In the architecture, the
CLAT must discover the PLAT-side translation IPv6 prefix. This
document defines a mechanism for CLAT to learn the IPv6 prefix used
for protocol translation on an access network.
Status of This Memo
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This Internet-Draft will expire on March 19, 2015.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2
3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 3
4. Client-Server Interaction . . . . . . . . . . . . . . . . . . 3
5. DHCPv6 Options . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. PLAT IPv6 PREFIX Option . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
464XLAT describes an IPv4-over-IPv6 solution as one of the techniques
for IPv4 service extension and encouragement of IPv6 deployment. The
464XLAT architecture uses IPv4/IPv6 translation standardized in
[RFC6145] and [RFC6146]. It encourages the IPv6 transition by making
IPv4 service reachable across IPv6-only networks and providing IPv6
and IPv4 connectivity to single-stack IPv4 or IPv6 servers and peers.
Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis
[RFC7050] describes a method for detecting the presence of DNS64 and
for learning the IPv6 prefix used for protocol translation on an
access network. But it is difficult and depends on DNS64.
This document defines a mechanism for CLAT to learn the IPv6 prefix
used for protocol translation on an access network. One new DHCPv6
option is defined to inform the CLAT of the IPv6 prefix used for IPv6
address synthesis.
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
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3. Solution Overview
In the 464XLAT architecture, the CLAT must discover the PLAT-side
translation IPv6 prefix used as a destination of the PLAT. The CLAT
will use this prefix as the destination of all translation packets
that require stateful translation to the IPv4 Internet.
The CLAT implements OPTION_V6_PLATPREFIX, which is a DHCPv6 option
containing the IPv6 prefix used as a destination of the PLAT. The
client includes this option within the ORO option in its DHCPv6
request, indicates its support for the IPv6 prefix to the DHCP
server.
OPTION_V6_PLATPREFIX is also implemented by the server to identify
the client which support IPv6 prefix. With this option, the server
informs the client of the IPv6 prefix used as a destination of the
PLAT.
4. Client-Server Interaction
The following diagram shows the client/server message flow and how
the DHCPv6 option OPTION_V6_PLATPREFIX is used. In each step, the
relevant DHCPv6 message is given above the arrow and the
OPTION_V6_PLATPREFIX below the arrow.
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DHCPv6 Client DHCPv6 Server
| Solicit |
Step 1 |----------------------------------------------------->|
| ORO with OPTION_V6_PLATPREFIX |
| |
| ADVERTISE |
Step 2 |<-----------------------------------------------------|
| OPTION_V6_PLATPREFIX (platv6-prefix with |
| PLAT-side translation IPv6 prefix) |
| |
| REQUEST |
Step 3 |----------------------------------------------------->|
| OPTION_V6_PLATPREFIX (platv6-prefix with |
| CLAT-side translation IPv6 prefix) |
| |
| REPLY |
Step 4 |<-----------------------------------------------------|
| OPTION_V6_PLATPREFIX (platv6-prefix with |
| CLAT-side translation IPv6 prefix) |
| |
Figure 1: Server/Client Interaction Procedure
The DHCPv6 Server and Client MAY implement the OPTION_V6_PLATPREFIX.
A Client that intends to dynamically discover the PLAT-side
translation IPv6 prefix SHOULD include the code of
OPTION_V6_PLATPREFIX in the ORO when it sends a Solicit message.
When a DHCPv6 server replies with a ADVERTISE message, it SHOULD
include the platv6-prefix with PLAT-side transition IPv6 prefix. The
OPTION_V6_PLATPREFIX is used by the server to inform the client of
the PLAT-side transition IPv6 prefix.
When the client sends a REQUEST message, it SHOULD include the
platv6-prefix with CLAT-side translation IPv6 prefix. The
OPTION_V6_PLATPREFIX is used by the client to inform the server of
the transition IPv6 prefix.
5. DHCPv6 Options
5.1. PLAT IPv6 PREFIX Option
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_V6_PLATPREFIX | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| platv6-prelen | |
+-+-+-+-+-+-+-+-+ platv6-prefix .
. (variable length) .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o option-code: OPTION_V6_PLATPREFIX (TBA1)
o option-length: 1 + length of platv6-prefix, specified in bytes.
o platv6-prelen: 8-bit field expressing the bit mask length of the
IPv6 prefix specified in platv6-prefix.
o platv6-prefix: The IPv6 prefix that the server uses to inform the
client of the IPv6 prefix used for IPv6 address synthesis.
6. Security Considerations
TBA
7. IANA Considerations
This document defines one new DHCPv6 option, the OPTION_V6_PLATPREFIX
option in Section 4.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
8.2. Informative References
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
Authors' Addresses
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Wendong Wang
BUPT University
Beijing University of Posts and Telecommunications (BUPT)
Beijing 100876
P.R.China
Phone: +86-10-6228-1175
Email: wdwang@bupt.edu.cn
Lanshan Zhang
BUPT University
Beijing University of Posts and Telecommunications (BUPT)
Beijing 100876
P.R.China
Phone: +86-13146885878
Email: zls326@sina.com
Xirong Que
BUPT University
Beijing University of Posts and Telecommunications (BUPT)
Beijing 100876
P.R.China
Phone: +86-10-6228-3411
Email: rongqx@bupt.edu.cn
Lishan Li
Tsinghua University
Beijing 100084
P.R.China
Phone: +86-15201441862
Email: lilishan9248@126.com
Yuqi Wang
BUPT University
Beijing University of Posts and Telecommunications (BUPT)
Beijing 100876
P.R.China
Email: wyqbupt@163.com
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