One document matched: draft-cheshire-pcp-unsupp-family-01.txt

Differences from draft-cheshire-pcp-unsupp-family-00.txt

PCP working group                                            S. Cheshire
Internet-Draft                                                     Apple
Updates: 6887 (if approved)                                 May 29, 2013
Intended status: Standards Track
Expires: November 30, 2013


                      PCP Unsupported Family Error
                  draft-cheshire-pcp-unsupp-family-01

Abstract

   The Port Control Protocol allows clients to request mappings in NAT
   gateways and firewalls.  The PCP UNSUPP_FAMILY error code enables PCP
   servers to inform clients when the requested external address family
   is not supported.

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 http://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 November 30, 2013.

Copyright Notice

   Copyright (c) 2013 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.



Cheshire                Expires November 30, 2013               [Page 1]

Internet-Draft              PCP UNSUPP_FAMILY                   May 2013


1.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   "Key words for use in RFCs to Indicate Requirement Levels" [RFC2119].


2.  Introduction

   The Port Control Protocol [RFC6887] allows clients to request
   mappings in NAT gateways and firewalls.  A client can request a
   mapping to an external IPv4 address or to an external IPv6 address.
   The client signifies which family of external address it desires by
   the type of address it puts into the Suggested External Address
   field.

   If the client wants an external IPv4 address, then it populates the
   Suggested External Address field with an IPv4-mapped IPv6 address
   (the first 80 bits set to zero, the next 16 set to one).  This
   includes the case of the all-zeros IPv4 address (::ffff:0:0).

   If the client wants an external IPv6 address, then it populates the
   Suggested External Address field with a native IPv6 address.  This
   includes the case of the all-zeros IPv6 address (::).

   However, some devices may not be able to provide the requested
   external address family.  For example, an IPv4-only NAT cannot
   provide an external IPv6 address.

   Note that while the specific address placed in the Suggested External
   Address field is merely a suggestion that the PCP server is free to
   ignore, the address family is not.  If the suggested address *family*
   cannot be provided by this PCP server, then it MUST return a PCP
   error reply containing the UNSUPP_FAMILY error code.

   The ability to provide the requested external address family may
   depend on the client's internal address.  For example, a gateway that
   supports traditional NAT44, and native IPv6, but not NAT64, is able
   to provide mappings from an internal IPv4 address to an external IPv4
   address, and mappings from an internal IPv6 address to an external
   IPv6 address, but not mappings from an internal IPv6 address to an
   external IPv4 address.  When such a gateway receives a request to map
   an internal IPv4 address to an external IPv4 address it MUST return
   an external IPv4 address, if available, but when it receives a
   request to map an internal IPv6 address to an external IPv4 address
   it MUST return an UNSUPP_FAMILY error.




Cheshire                Expires November 30, 2013               [Page 2]

Internet-Draft              PCP UNSUPP_FAMILY                   May 2013


3.  IANA Considerations

   IANA should allocate the following PCP Result Code:

   14 UNSUPP_FAMILY: Unsupported external address family, e.g., IPv6 in
      a NAT that handles only IPv4.  This is a long lifetime error.


4.  Security Considerations

   This new error code leaks no sensitive information and creates no new
   security vulnerabilities.


5.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC6887]  Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
              Selkirk, "Port Control Protocol (PCP)", RFC 6887,
              April 2013.


Author's Address

   Stuart Cheshire
   Apple Inc.
   1 Infinite Loop
   Cupertino, California  95014
   USA

   Phone: +1 408 974 3207
   Email: cheshire@apple.com

















Cheshire                Expires November 30, 2013               [Page 3]