Teredo Extensions
RFC 6081

Internet Engineering Task Force (IETF)                         D. Thaler
Request for Comments: 6081                                     Microsoft
Updates: 4380                                               January 2011
Category: Standards Track
ISSN: 2070-1721

                           Teredo Extensions

Abstract

   This document specifies a set of extensions to the Teredo protocol.
   These extensions provide additional capabilities to Teredo, including
   support for more types of Network Address Translations (NATs) and
   support for more efficient communication.

Status of This Memo

   This is an Internet Standards Track document.

   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
   Internet Standards is available in Section 2 of RFC 5741.

   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/rfc6081.

Copyright Notice

   Copyright (c) 2011 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.

Thaler                       Standards Track                    [Page 1]
RFC 6081                    Teredo Extensions               January 2011

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
     3.1.  Symmetric NAT Support Extension  . . . . . . . . . . . . .  9
     3.2.  UPnP-Enabled Symmetric NAT Extension . . . . . . . . . . . 11
     3.3.  Port-Preserving Symmetric NAT Extension  . . . . . . . . . 13
     3.4.  Sequential Port-Symmetric NAT Extension  . . . . . . . . . 14
     3.5.  Hairpinning Extension  . . . . . . . . . . . . . . . . . . 15
     3.6.  Server Load Reduction Extension  . . . . . . . . . . . . . 17
   4.  Message Syntax . . . . . . . . . . . . . . . . . . . . . . . . 18
     4.1.  Trailers . . . . . . . . . . . . . . . . . . . . . . . . . 18
     4.2.  Nonce Trailer  . . . . . . . . . . . . . . . . . . . . . . 19
     4.3.  Alternate Address Trailer  . . . . . . . . . . . . . . . . 19
     4.4.  Neighbor Discovery Option Trailer  . . . . . . . . . . . . 20
     4.5.  Random Port Trailer  . . . . . . . . . . . . . . . . . . . 21
   5.  Protocol Details . . . . . . . . . . . . . . . . . . . . . . . 22
     5.1.  Common Processing  . . . . . . . . . . . . . . . . . . . . 22
       5.1.1.  Refresh Interval . . . . . . . . . . . . . . . . . . . 22
       5.1.2.  Trailer Processing . . . . . . . . . . . . . . . . . . 23
     5.2.  Symmetric NAT Support Extension  . . . . . . . . . . . . . 23
       5.2.1.  Abstract Data Model  . . . . . . . . . . . . . . . . . 24
       5.2.2.  Timers . . . . . . . . . . . . . . . . . . . . . . . . 24
       5.2.3.  Initialization . . . . . . . . . . . . . . . . . . . . 24
       5.2.4.  Message Processing . . . . . . . . . . . . . . . . . . 24
     5.3.  UPnP-Enabled Symmetric NAT Extension . . . . . . . . . . . 25
       5.3.1.  Abstract Data Model  . . . . . . . . . . . . . . . . . 26
       5.3.2.  Timers . . . . . . . . . . . . . . . . . . . . . . . . 26
       5.3.3.  Initialization . . . . . . . . . . . . . . . . . . . . 27
       5.3.4.  Message Processing . . . . . . . . . . . . . . . . . . 28
       5.3.5.  Shutdown . . . . . . . . . . . . . . . . . . . . . . . 29
     5.4.  Port-Preserving Symmetric NAT Extension  . . . . . . . . . 30
       5.4.1.  Abstract Data Model  . . . . . . . . . . . . . . . . . 30
       5.4.2.  Timers . . . . . . . . . . . . . . . . . . . . . . . . 31
       5.4.3.  Initialization . . . . . . . . . . . . . . . . . . . . 32
       5.4.4.  Message Processing . . . . . . . . . . . . . . . . . . 32
     5.5.  Sequential Port-Symmetric NAT Extension  . . . . . . . . . 35
       5.5.1.  Abstract Data Model  . . . . . . . . . . . . . . . . . 35
       5.5.2.  Timers . . . . . . . . . . . . . . . . . . . . . . . . 36
       5.5.3.  Initialization . . . . . . . . . . . . . . . . . . . . 37