Mitigation against IPv6 Router Advertisements flooding
draft-moonesamy-ra-flood-limit-01

Versions: 00 01                                                         
INTERNET-DRAFT                                              S. Moonesamy
Intended Status: Informational
Expires: June 22, 2014

                                                       December 19, 2013


         Mitigation against IPv6 Router Advertisements flooding
                   draft-moonesamy-ra-flood-limit-01


Abstract

   An IPv6 Router Advertisements flooding attack can cause a node to
   consume all CPU resources available making the system unusable and
   unresponsive. This document recommends some configurable variables as
   a mitigation against an IPv6 Router Advertisements flooding attack.


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   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



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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Router Advertisement Configuration Variables . . . . . . . . .  3
     2.1 MaxInterfacePrefixes . . . . . . . . . . . . . . . . . . . .  3
     2.2. MaxInterfaceRouters . . . . . . . . . . . . . . . . . . . .  3
     2.3. MaxRedirect . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Security Considerations  . . . . . . . . . . . . . . . . . . .  3
   4.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  4
   5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . .  4
   6.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  4
     6.1.  Normative References . . . . . . . . . . . . . . . . . . .  4
     6.2.  Informative References . . . . . . . . . . . . . . . . . .  4
   Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .  4


























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1.  Introduction

   The Neighbor Discovery protocol [RFC4861] describes the operation of
   IPv6 Router Advertisements (RAs) that are used to determine node
   configuration information during the IPv6 autoconfiguration process.
   A Router Advertisements flooding attack [RAFLOOD] can cause a node to
   consume all CPU resources available or cause kernel memory exhaustion
   making the system unusable and unresponsive.  The problem with rogue
   IPv6 Router Advertisement is documented in RFC 6104 [RFC6104].

   This document recommends some configurable variables as a mitigation
   against a Router Advertisements flooding attack.

2.  Router Advertisement Configuration Variables

   A host will silently discard a Router Advertisement once the
   configurable limit is reached.  Default values are specified to make
   it unnecessary to configure any of these variables.

2.1 MaxInterfacePrefixes

   This variable is the maximum number of prefixes created per interface
   by Router Advertisements.

   Default: 16

2.2. MaxInterfaceRouters

   This variable is the maximum number of default routers created per
   interface by Route Advertisements.

   Default: 16

2.3. MaxRedirect

   This variable is the maximum number of dynamic routes created via
   ICMPv6 Redirect messages.

   Default: 4096


3.  Security Considerations

   The Router Advertisements flooding attack can cause a denial-of-
   service.  The configuration variables described in this document can
   be used to limit the scope of the attack.  There is a high
   probability that valid Router Advertisement information may be lost
   even with the mitigation described in this document.  It is



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   recommended to log a system alert about the configurable limit
   reached.

4.  IANA Considerations

   [RFC Editor: please remove this section]

5. Acknowledgments

   Marc Heuse published an advisory about the IPv6 Router Advertisements
   flooding attack in 2011.  The authors would like to thank David
   Farmer, Joel M. Halpern, Marc Heuse and Arturo Servin for
   contributing to the document.

6.  References

6.1.  Normative References

   [RFC4861] Narten, T., Nordmark, E., and W. Simpson, "Neighbor
              Discovery for IP Version 6 (IPv6)", RFC 2461, December
              1998.

6.2.  Informative References

   [RFC6104] Chown, T. and S. Venaas, "Rogue IPv6 Router Advertisement
              Problem Statement", RFC 6104, February 2011.

   [RAFLOOD] <http://www.mh-sec.de/downloads/mh-RA_flooding_CVE-2010-
              multiple.txt>

Appendix A

   The default values mentioned in Section 2 have been implemented in
   FreeBSD, NetBSD and OpenBSD.

Authors' Addresses


   S. Moonesamy
   76, Ylang Ylang Avenue
   Quatres Bornes
   Mauritius

   Email: sm+ietf@elandsys.com







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