Network Working Group                                       B. Carpenter
Internet-Draft                                         Univ. of Auckland
Intended status: Informational                               B. Liu, Ed.
Expires: September 1, 2019                           Huawei Technologies
                                                       February 28, 2019


    Scenarios and Requirements for Layer 2 Autonomic Control Planes
                draft-carpenter-anima-l2acp-scenarios-00

Abstract

   This document discusses scenarios and requirements for Autonomic
   Control Planes (ACPs) constructed and secured at Layer 2.  These
   would be alternatives to an ACP constructed and secured at the
   network layer.  A secure ACP is required as the substrate for the
   Generic Autonomic Signaling Protocol (GRASP) used by Autonomic
   Service Agents.

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   This Internet-Draft will expire on September 1, 2019.

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   the Trust Legal Provisions and are provided without warranty as
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Network Scenarios Suitable for a Layer 2 ACP  . . . . . . . .   2
   3.  Requirements for a Layer 2 Technology . . . . . . . . . . . .   3
   4.  Multiple Segments . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Implementation Status [RFC Editor: please remove] . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   5
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Appendix A.  Change log [RFC Editor: Please remove] . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

.  Introduction

   As defined in [I-D.ietf-anima-reference-model], the Autonomic Service
   Agent (ASA) is the atomic entity of an autonomic function, and it is
   instantiated on autonomic nodes.  When ASAs communicate with each
   other, they should use the Generic Autonomic Signaling Protocol
   (GRASP) [I-D.ietf-anima-grasp].  It is essential that such
   communication is strongly secured to avoid malicious interference
   with the Autonomic Infrastructure (ANI).

   For this reason, GRASP must run over a secure substrate that is
   isolated from regular data plane traffic.  This substrate is known as
   the Autonomic Control Plane (ACP).  A method for constructing an ACP
   at the network layer is described in
   [I-D.ietf-anima-autonomic-control-plane].  The present document
   discusses scenarios and requirements for constructing an ACP at layer
   2.

.  Network Scenarios Suitable for a Layer 2 ACP

   The ANI design is aimed at managed networks, as explained in the
   reference model [I-D.ietf-anima-reference-model].  For a wide area
   network (such as a large campus, a multi-site enterprise network, or
   a carrier network considered as a whole) it is appropriate to
   construct the ACP using network layer techniques and network layer
   security.  and that is the model described in
   [I-D.ietf-anima-autonomic-control-plane], However, in at least two
   cases an ACP covering a smaller geographical area may be appropriate:




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   1.  A small enterprise that is completely within one building or
       several adjacent buildings, but is large enough to require
       autonomic network management.

   2.  An enterprise that prefers in any case to segment its network
       into smaller units for management purposes.

   In either case, we assume that the L2 ACP may extend into the Network
   Operations Centre (NOC) so that it can be interfaced to traditional
   tools for Operations, Administration and Maintenance, as described in
   [RFC8368].  In the terminology of that document, an L2 ACP is an
   instance of a Generalized ACP.

.  Requirements for a Layer 2 Technology

   1.  The technology must support transmission of IPv6 packets
       according to [RFC8200].  Since GRASP can run on a single network
       segment using link-local addresses, there is not required to be
       an IPv6 router or DHCPv6 server.

   2.  The technology must support multicast.  If the switches are not
       completely transparent to layer 2 multicast, they must support
       Multicast Listener Discovery Version 2 (MLDv2) for IPv6
       [RFC3810].

   3.  The technology should have a minimum MTU of 1500 bytes.

   4.  The technology must support isolation of a given set of nodes
       (the "ACP VLAN").

   5.  The technology must support secure authorization for access to
       the ACP VLAN.  If the VLAN technology in use does not support
       password protection, a VLAN access control list could be used.

   6.  The technology should support both the normal dataplane VLAN and
       the ACP VLAN on the same physical sockets.  (Possibly the
       dataplane may be the native VLAN, i.e. frames with no VLAN tag.)

   7.  The technology should support line speed encryption of the ACP
       VLAN.

   8.  The technology should support wired/wireless bridging if
       relevant.

   9.  The technology should require minimal manual configuration of ACP
       nodes.  However, it is expected that the nodes will need to be
       preconfigured before deployment with the VLAN ID, and a password
       or encryption key if necessary.  A solution which is both secure



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       and self-configuring at Layer 2 is out of scope for this
       document.

   A small ACP software module will be needed in each autonomic node,
   whose job is to provide the GRASP core with the following information
   about the L2 ACP:

   1.  A signal that the L2 ACP is available and secure.

   2.  The current global scope IPv6 address that GRASP should use as
       its primary locator, preferably a ULA, if available.  As
       mentioned, if no such address is available, GRASP will simply
       operate with link-local addresses.

   3.  A list of [interface_index, link_local_address] pairs for all
       valid IPv6 interfaces attached to the L2 ACP.  The interface
       index is an integer for maximum portability between operating
       systems.

.  Multiple Segments

   This section is for further study.

   The L2 ACP could in principle be extended across multiple segments or
   even multiple sites by use of secure L2VPN technology.

.  Implementation Status [RFC Editor: please remove]

   A simple ACP software module emulating that needed for a secure L2
   ACP has been implemented, but it does not in fact verify security.
   It may be found at
   <https://github.com/becarpenter/graspy/blob/master/acp.py> and is
   briefly documented in
   <https://github.com/becarpenter/graspy/blob/master/graspy.pdf>.

.  Security Considerations

   The assumption of this document is that any Layer 2 solution chosen
   must have adequate security against interlopers and eavesdroppers.
   It should be noted that (at least in a wired network) this also
   requires adequate physical security to prevent access by unauthorized
   persons, including physical intrusion detection.

   The fact that an IPv6 router is not required in an L2 ACP excludes
   many Layer 3 vulnerabilities by construction.  No outside entity can
   generate link-local IPv6 packets, and no outside entity can send
   global scope packets to any autonomic node.




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.  IANA Considerations

   This document makes no request of the IANA.

.  Acknowledgements

   Excellent suggestions were made by TBD and other participants in the
   ANIMA WG.

.  References

9.1.  Normative References

   [RFC3810]  Vida, R., Ed. and L. Costa, Ed., "Multicast Listener
              Discovery Version 2 (MLDv2) for IPv6", RFC 3810,
              DOI 10.17487/RFC3810, June 2004,
              <https://www.rfc-editor.org/info/rfc3810>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

9.2.  Informative References

   [I-D.ietf-anima-autonomic-control-plane]
              Eckert, T., Behringer, M., and S. Bjarnason, "An Autonomic
              Control Plane (ACP)", draft-ietf-anima-autonomic-control-
              plane-18 (work in progress), August 2018.

   [I-D.ietf-anima-grasp]
              Bormann, C., Carpenter, B., and B. Liu, "A Generic
              Autonomic Signaling Protocol (GRASP)", draft-ietf-anima-
              grasp-15 (work in progress), July 2017.

   [I-D.ietf-anima-reference-model]
              Behringer, M., Carpenter, B., Eckert, T., Ciavaglia, L.,
              and J. Nobre, "A Reference Model for Autonomic
              Networking", draft-ietf-anima-reference-model-10 (work in
              progress), November 2018.

   [RFC8368]  Eckert, T., Ed. and M. Behringer, "Using an Autonomic
              Control Plane for Stable Connectivity of Network
              Operations, Administration, and Maintenance (OAM)",
              RFC 8368, DOI 10.17487/RFC8368, May 2018,
              <https://www.rfc-editor.org/info/rfc8368>.





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Appendix A.  Change log [RFC Editor: Please remove]

   draft-carpenter-anima-l2acp-scenarios-00, 2019-02-28:

   Initial version

Authors' Addresses

   Brian Carpenter
   The University of Auckland
   School of Computer Science
   University of Auckland
   PB 92019
   Auckland  1142
   New Zealand

   Email: brian.e.carpenter@gmail.com


   Bing Liu (editor)
   Huawei Technologies
   Q14, Huawei Campus
   No.156 Beiqing Road
   Hai-Dian District, Beijing  100095
   P.R. China

   Email: leo.liubing@huawei.com
























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