Multiple Interfaces and Provisioning Domains Problem Statement
RFC 6418

Internet Engineering Task Force (IETF)                       M. Blanchet
Request for Comments: 6418                                      Viagenie
Category: Informational                                         P. Seite
ISSN: 2070-1721                                  France Telecom - Orange
                                                           November 2011

     Multiple Interfaces and Provisioning Domains Problem Statement

Abstract

   This document describes issues encountered by a node attached to
   multiple provisioning domains.  This node receives configuration
   information from each of its provisioning domains, where some
   configuration objects are global to the node and others are local to
   the interface.  Issues such as selecting the wrong interface to send
   traffic happen when conflicting node-scoped configuration objects are
   received and inappropriately used.  Moreover, other issues are the
   result of simultaneous attachment to multiple networks, such as
   domain selection or addressing and naming space overlaps, regardless
   of the provisioning mechanism.  While multiple provisioning domains
   are typically seen on nodes with multiple interfaces, this document
   also discusses situations involving single-interface nodes.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see 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/rfc6418.

Blanchet & Seite              Informational                     [Page 1]
RFC 6418          Multiple Interfaces Problem Statement    November 2011

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.

Table of Contents

   1. Introduction ....................................................3
   2. Terminology .....................................................4
   3. Scope and Existing Work .........................................4
      3.1. Interactions Below IP ......................................4
      3.2. MIF Node Characterization ..................................5
      3.3. Host Requirements ..........................................5
      3.4. Mobility and Other IP Protocols ............................6
      3.5. Address Selection ..........................................6
      3.6. Finding and Sharing IP Addresses with Peers ................7
      3.7. Provisioning Domain Selection ..............................7
      3.8. Session Management .........................................8
      3.9. Sockets API ................................................9
   4. MIF Issues ......................................................9
      4.1. DNS Resolution Issues ......................................9
      4.2. Node Routing ..............................................12
      4.3. Conflicting Policies ......................................13
      4.4. Session Management ........................................14
      4.5. Single Interface on Multiple Provisioning Domains .........14
   5. Underlying Problems and Causes .................................15
   6. Security Considerations ........................................17
   7. Contributors ...................................................18
   8. Acknowledgements ...............................................18
   9. Informative References .........................................18

Blanchet & Seite              Informational                     [Page 2]
RFC 6418          Multiple Interfaces Problem Statement    November 2011

1.  Introduction

   A multihomed node may have multiple provisioning domains (via
   physical and/or virtual interfaces).  For example, a node may be