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Versions: 00 draft-ietf-ipsecme-p2p-vpn-problem

IPsecME Working Group                                             Y. Nir
Internet-Draft                                               Check Point
Intended status: Informational                               J. Veizades
Expires: April 16, 2012                                          Juniper
                                                              C. Ulliott
                                                              J. Mendoza
                                                        October 14, 2011

            Creating Large Scale Mesh VPNs Problem Statement


   This document presents the problem of configuring a large number of
   IKE/IPsec systems in such a way that any two of them can use IPsec to
   protect the traffic between them.  Manual configuration of all
   possible tunnels is too cumbersome in such cases, so an automated
   method is needed.

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 April 16, 2012.

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

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   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
     1.1.  Conventions Used in This Document  . . . . . . . . . . . .  4
   2.  Use Cases  . . . . . . . . . . . . . . . . . . . . . . . . . .  5
     2.1.  The Service Provider Use Case  . . . . . . . . . . . . . .  5
     2.2.  Cross Domain Mesh Use Case . . . . . . . . . . . . . . . .  5
       2.2.1.  Scenario 1 . . . . . . . . . . . . . . . . . . . . . .  5
       2.2.2.  Scenario 2 . . . . . . . . . . . . . . . . . . . . . .  5
       2.2.3.  Scenario 3 . . . . . . . . . . . . . . . . . . . . . .  6
     2.3.  The Consultant Use Case  . . . . . . . . . . . . . . . . .  6
       2.3.1.  Scenario A: Mobile worker and multiple domains . . . .  6
       2.3.2.  Scenario B: Consultants sharing securely . . . . . . .  6
   3.  Security Considerations  . . . . . . . . . . . . . . . . . . .  8
   4.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
   5.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
   6.  Normative References . . . . . . . . . . . . . . . . . . . . . 11
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12

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1.  Introduction

   IPsec ([RFC4301]) is used in several different cases, including
   tunnel-mode site-to-site VPNs and Remote Access VPNs.  Host to host
   communication employing transport mode also exists, but is far less
   commonly deployed.  The subject of this document is large scale
   deployments.  These may be a large collection of VPN gateways and
   hosts, all administered within the same administrative domain, or
   they may be a smaller collection of VPN gateways, with many remote
   access clients connecting to any of them, or they may be several
   collections of gateways, each collection administered by a different
   domain, or they may be combinations of all of the above.

   Section 4.4 of RFC 4301 describes the major IPsec databases needed
   for IPsec processing.  It requires an extensive configuration for
   each tunnel, so manually configuring a "mesh" of several gateways
   becomes inconvenient.

   One way to handle this is what has been termed a "star topology", or
   a "trunk topology".  In this case one gateway, or a few gateways are
   defined as "core gateways", while the rest, whether remote-access
   clients or gateways are defined as "satellites".  The satellites
   never connect to other satellites.  They only open tunnels with the
   core gateways.

   For a large number of gateways in one administrative domain, one
   gateway may be defined as the core, and the rest of the gateways and
   remote access clients connect only to that gateway.  If the packet
   destination is behind another gateway, then the core gateway will re-
   encrypt the traffic, and send it through the other tunnel.  If we
   have two collections of gateways under two administrative domains,
   then each domain has its own "core", and the administrators only need
   to define an IPsec tunnel between the two cores.  This tunnel is
   often referred to as a "trunk".

   The problem with stars and trunks is that it creates a high load on
   the core gateways as well as on the trunk connection.  This load is
   both in processing power and in network bandwidth.  A single packet
   in the trunk scenario can be encrypted and decrypted three times.  It
   would be much preferable if these gateways and clients could initiate
   tunnels between them, bypassing the core gateways.  Additionally, the
   path bandwidth to these core gateways may be lower than that of the
   path between the satellites.  For example, two remote access users
   may be in the same building with high-speed wifi (for example, at an
   IETF meeting).  Channeling their conversation through the core
   gateways of their respective employers seems extremely wasteful, as
   well as having lower bandwidth.

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   The challenge is how to build large scale, fully meshed IPsec
   protected networks that can dynamically change with minimum
   administrative overhead.

   The difficulty is that all the configuration mentioned in RFC 4301 is
   not superfluous.  IKE implementations need to know the identity and
   credentials of all possible peer systems, as well as the addresses of
   hosts and/or networks behind them.  A simplified mechanism for
   establishing ad-hoc tunnels is needed.  Section 2 contains several
   use cases that led to the publishing of this document.

1.1.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119].

   "Administrative Domain" is used in this document for the entity,
   whether human, team, or computer, that configures VPN gateways and
   clients.  Gateways are said to be under the same administrative
   domain if they are configured by a single entity and implement the
   same policy.  Some products have the ability to configure multiple
   VPN gateways or clients, which would solve the problem presented in
   this document for gateways under the same administrative domain, but
   they do not solve the problem for multiple administrative domains.

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2.  Use Cases

   This section presents the use cases that have motivated this document
   in no particular order.

2.1.  The Service Provider Use Case

   A service provider wishes to control communication between network
   elements with authentication and encryption as provided by standard
   protocols like IPsec.  This is possible today but the amount of
   configuration information on each system is currently order n squared
   so from an operational standpoint this can be challenging as the size
   of the enterprise network grows.  In short service providers wish to
   minimize the configuration data that is required by any one system to
   initiate a secure communication link to any other arbitrary system
   that is part of the service provider enterprise.

   These same service providers wish to extend these secure
   communication links to partners that have similar systems.  Again
   they wish to minimize the amount of configuration needed to initiate
   these secure connections to arbitrary systems at an arbitrary
   partner.  Additionally they required a directory of connection
   information that can be updated independently to manage the identity
   of the connection endpoints at each one of their partners.

2.2.  Cross Domain Mesh Use Case

   This section describes requirements for dynamically creating a mesh
   of VPN endpoints although those endpoints belong to different
   administrative domains.

2.2.1.  Scenario 1

   Multiple users, connected to a corporate remote access solution are
   participating in high bandwidth peer to peer communications.  It is
   required that to optimise bandwidth and latency (subject to policy),
   the solution is able to establish links between remote peers rather
   than through a central gateway.

2.2.2.  Scenario 2

   Rather than remote hosts, the next scenario covers the connectivity
   between gateways.  Behind each gateway there are a number of
   individual hosts who aren't aware of the protection being offered by
   the gateway.  As each client send traffic to a host at a different
   site, the gateway is required to identify the location of the remote
   host and selects the most approprate gateway.  Having made this
   decision, it dynamically establishes a secure tunnel and forwards the

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2.2.3.  Scenario 3

   The third scenario is a combination of the first two, where a remote
   user is no longer tied to using a specific remote access gateway.
   Should the remote host need to communicate with an entity protected
   by a gateway as described above, it would be possible for it to
   identify a suitable gateway and establish a dynamic SA / tunnel and
   communicate via the most effective route (subject to policy) It is
   essential that any solution that meets the above scenarios, that we
   specify a mechanism for identifying permitted hosts / gateways and
   deploying a policy to each gateway and participating host.  The
   solution also needs to work in an environment where gateways / hosts
   are administered by different entitites or management domains.

2.3.  The Consultant Use Case

   This section describes use cases for a consultant who works for
   multiple organizations but is not an employee of any of them.

2.3.1.  Scenario A: Mobile worker and multiple domains

   A consultant is hired by corporations (A and B) each of them with
   their own isolated domains and resources protected with IPsec
   authentication.  The consultant has signed NDA and the corporation
   granted some level of trust in the form of an authentication ID.
   This level of trust allows the contractor to access secured resources
   and networks protected by IPsec until such trust is revoked.

   In any given work week the consultant would be providing services on
   site or remotely to multiple corporations.  This is possible today,
   yet unmanageable due to the amount of configuration required in order
   for the consultant to dynamically identify the parameters to use
   o  He/She needs to get connected to secure resources when on premises
      (E2E client to server secured connection)
   o  He/She needs to use a secure access point when working remotely
      (Client to Edge connection)

   One key aspect of this problem is that the consultant may be
   providing consulting services to Corp A and Corp B, for privacy
   reasons this information should be protected.

2.3.2.  Scenario B: Consultants sharing securely

   Consultant team A and team B have hired by corporation C and are
   working together in a project that requires collaboration, however

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   because they are from different consulting firms half of the
   consultants are based in WA and half in CA.  As in the scenario above
   they have been entrusted with authentication ID.  They have a need to
   share folders with sensitive files in order to work efficiently
   towards a tight deadline.

   They have a need to securely handle this information hence they have
   a need to discover what type of security should be used when
   attempting to share information among themselves.

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3.  Security Considerations

   The solution to the problems presented in this draft may involve
   dynamic updates to databases defined by RFC 4301, such as the
   Security Policy Database (SPD) or the Peer Authorization Database

   RFC 4301 is silent about the way these databases are populated, and
   it is implied that these databases are static and pre-configured by a
   human.  Allowing dynamic updates to these databases must be thought
   out carefully, because it allows the protocol to alter the security
   policy that the IPsec endpoints implement.

   One obvious attack to watch out for is stealing traffic to a
   particular site.  The IP address for www.example.com is
   If we add an entry to an IPsec endpoint's SPD that says that traffic
   to is protected through peer Gw-Mallory, then this allows
   Gw-Mallory to either pretend to be www.example.com or to proxy and
   read all traffic to that site.  Updates to this database requires a
   clear trust model.

   More to be added.

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4.  IANA Considerations

   No actions are required from IANA for this informational document.

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5.  Acknowledgements

   The authors would like to thank Geoffrey Huang, Suresh Melam, Andreas
   Stephen, and Brian Weis for their discussion and comments on early
   versions of this draft.  We would also like to thank Stephen Hanna
   for gathering the group that has produced this draft.

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6.  Normative References

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

   [RFC4301]  Kent, S. and K. Seo, "Security Architecture for the
              Internet Protocol", RFC 4301, December 2005.

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Authors' Addresses

   Yoav Nir
   Check Point Software Technologies Ltd.
   5 Hasolelim st.
   Tel Aviv  67897

   Email: ynir@checkpoint.com

   John Veizades
   Juniper Networks, Inc.
   1194 N. Mathilda ave.
   Sunnyvale, CA  94089

   Email: jveizades at juniper dot net

   Chris Ulliott
   Hubble Road
   Cheltenham  GL51 0EX

   Email: Chris.Ulliott@cesg.gsi.gov.uk

   Jorge Coronel Mendoza
   Microsoft Corporation
   1 Microsoft Way
   Redmond, WA  98052

   Email: jcoronel@microsoft.com

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