Dissemination of Flow Specification Rules for IPv6
draft-ietf-idr-flow-spec-v6-04

IDR Working Group                                         R. Raszuk, Ed.
Internet-Draft                                              NTT MCL Inc.
Updates: RFC5575 (if approved)                              B. Pithawala
Intended status: Standards Track                           Cisco Systems
Expires: August 1, 2014                                     D. McPherson
                                                          Verisign, Inc.
                                                                A. Karch
                                                           Cisco Systems
                                                        January 28, 2014

           Dissemination of Flow Specification Rules for IPv6
                     draft-ietf-idr-flow-spec-v6-04

Abstract

   Dissemination of Flow Specification Rules [RFC5575] provides a
   protocol extension for propagation of traffic flow information for
   the purpose of rate limiting or filtering.  The [RFC5575] specifies
   those extensions for IPv4 protocol data packets.

   This specification extends the current [RFC5575] and defines changes
   to the original document in order to make it also usable and
   applicable to IPv6 data packets.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on August 1, 2014.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   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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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  IPv6 Flow Specification encoding in BGP . . . . . . . . . . .   2
   3.  IPv6 Flow Specification types changes . . . . . . . . . . . .   3
     3.1.  Order of Traffic Filtering Rules  . . . . . . . . . . . .   5
   4.  IPv6 Flow Specification Traffic Filtering Action changes  . .   6
   5.  Security considerations . . . . . . . . . . . . . . . . . . .   7
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   The growing amount of IPv6 traffic in private and public networks
   requires the extension of tools used in the IPv4 only networks to be
   also capable of supporting IPv6 data packets.

   In this document authors analyze the differences of IPv6 [RFC2460]
   flows description from those of traditional IPv4 packets and propose
   subset of new encoding formats to enable Dissemination of Flow
   Specification Rules [RFC5575] for IPv6.

   This specification should be treated as an extension of base
   [RFC5575] specification and not its replacement.  It only defines the
   delta changes required to support IPv6 while all other definitions
   and operation mechanisms of Dissemination of Flow Specification Rules
   will remain in the main specification and will not be repeated here.

2.  IPv6 Flow Specification encoding in BGP

   The [RFC5575] defines a new SAFIs (133 for IPv4) and (134 for VPNv4)
   applications in order to carry corresponding to each such application
   flow specification.

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   This document will redefine the [RFC5575] SAFIs in order to make them
   AFI specific and applicable to both IPv4 and IPv6 applications.

   The following changes are defined:

      "SAFI 133 for IPv4 dissemination of flow specification rules" to
      now be defined as "SAFI 133 for dissemination of unicast flow
      specification rules"

      "SAFI 134 for VPNv4 dissemination of flow specification rules" to
      now be defined as "SAFI 134 for dissemination of L3VPN flow
      specification rules"

   For both SAFIs the indication to which address family they are
   referring to will be recognized by AFI value (AFI=1 for IPv4 or
   VPNv4, AFI=2 for IPv6 and VPNv6 respectively).  Such modification is
   fully backwards compatible with existing implementation and
   production deployments.

   It needs to be observed that such choice of proposed encoding is
   compatible with filter validation against routing reachability
   information as described in section 6 of RFC5575.  Validation tables
   will now be performed according to the following rules.

      Flow specification received over AFI/SAFI=1/133 will be validated
      against routing reachability received over AFI/SAFI=1/1

      Flow specification received over AFI/SAFI=1/134 will be validated
      against routing reachability received over AFI/SAFI=1/128

      Flow specification received over AFI/SAFI=2/133 will be validated
      against routing reachability received over AFI/SAFI=2/1

      Flow specification received over AFI/SAFI=2/134 will be validated
      against routing reachability received over AFI/SAFI=2/128

3.  IPv6 Flow Specification types changes

   The following component types are redefined or added for the purpose
   of accommodating new IPv6 header encoding.  Unless otherwise stated
   all other types as defined in RFC5575 apply to IPv6 packets as is.

   Type 1 - Destination IPv6 Prefix

      Encoding: <type (1 octet), prefix offset (1 octet), prefix length
      (1 octet), prefix>

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      Defines the destination prefix to match.  Prefix offset has been
      defined to allow for flexible matching on part of the IPv6 address
      where we want to skip (don't care) of N first bits of the address.
      This can be especially useful where part of the IPv6 address
      consists of an embedded IPv4 address and matching needs to happen
      only on the embedded IPv4 address.  The encoded prefix contains
      enough octets for the bits used in matching (length minus offset
      bits).

   Type 2 - Source IPv6 Prefix

      Encoding: <type (1 octet), prefix offset (1 octet), prefix length
      (1 octet), prefix>

      Defines the source prefix to match.  Prefix offset has been
      defined to allow for flexible matching on part of the IPv6 address
      where we want to skip (don't care) of N first bits of the address.
      This can be especially useful where part of the IPv6 address
      consists of an embedded IPv4 address and matching needs to happen
      only on the embedded IPv4 address.  The encoded prefix contains
      enough octets for the bits used in matching (length minus offset
      bits).

   Type 3 - Next Header

      Encoding: <type (1 octet), [op, value]+>

      Contains a set of {operator, value} pairs that are used to match
      the last Next Header value octet in IPv6 packets.  The operator
      byte is encoded as specified in component type 3 of [RFC5575].

      While IPv6 allows for more then one Next Header field in the
      packet the main goal of Type 3 flow specification component is to
      match on the subsequent IP protocol value.  Therefor the
      definition is limited to match only on last Next Header field in
      the packet.

   Type 12 - Fragment

      Encoding: <type (1 octet), [op, bitmask]+>

      Uses bitmask operand format defined above.  Bit-7 is not used and
      MUST be 0 to provide backwards-compatibility with the definition
      in RFC5575.

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                       0   1   2   3   4   5   6   7
                     +---+---+---+---+---+---+---+---+
                     |   Reserved    |LF |FF |IsF| 0 |
                     +---+---+---+---+---+---+---+---+

      Bitmask values:

      + Bit 6 - Is a fragment (IsF)

      + Bit 5 - First fragment (FF)

      + Bit 4 - Last fragment (LF)

   Type 13 - Flow Label - New type

      Encoding: <type (1 octet), [op, value]+>

      Contains a set of {operator, value} pairs that are used to match
      the 20-bit Flow Label field [RFC2460].  The operator byte is
      encoded as specified in the component type 3 of [RFC5575].

   Type 14 - Traffic Class - New type

      Encoding: <type (1 octet), [op, value]+>

      Contains a set of {operator, value} pairs that are used to match
      the full Traffic Class 8-bit field [RFC2460] encoded in a single
      octet.  The operator byte is encoded as specified in component
      type 3 of [RFC5575].

   The following example demonstrates the new prefix encoding for: "all
   packets to ::1234:5678:9A00:0/80-104 from 192::/8 and port {range
   [137, 139] or 8080}".

    +---------------------------+-------------+-------------------------+
    | destination               | source      | port                    |
    +---------------------------+-------------+-------------------------+
    | 0x01 40 68 12 34 56 78 9A | 02 00 08 c0 | 04 03 89 45 8b 91 1f 90 |
    +---------------------------+-------------+-------------------------+

3.1.  Order of Traffic Filtering Rules

   The orignal definition for the order of traffic filtering rules can
   be reused with new consideration for the IPv6 prefix offset.  As long
   as the offsets are equal, the comparison is the same, retaining
   longest-prefix-match semantics.  If the offsets are not equal, the

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   lowest offset has precedence, as this flow matches the most
   significant bit.

   Pseudocode:

      flow_rule_v6_cmp (a, b)
      {
          comp1 = next_component(a);
          comp2 = next_component(b);
          while (comp1 || comp2) {
              // component_type returns infinity on end-of-list
              if (component_type(comp1) < component_type(comp2)) {
                  return A_HAS_PRECEDENCE;
              }
              if (component_type(comp1) > component_type(comp2)) {
                  return B_HAS_PRECEDENCE;
              }

              if (component_type(comp1) == IPV6_DESTINATION || IPV6_SOURCE) {
                  // offset not equal, lowest offset has precedence
                  // offset equal ...
                  common_len = MIN(prefix_length(comp1), prefix_length(comp2));
                  cmp = prefix_compare(comp1, comp2, offset, common_len);
                  // not equal, lowest value has precedence
                  // equal, longest match has precedence
              } else {
                  common =
                     MIN(component_length(comp1), component_length(comp2));
                  cmp = memcmp(data(comp1), data(comp2), common);
                  // not equal, lowest value has precedence
                  // equal, longest string has precedence
              }
          }

          return EQUAL;
      }

4.  IPv6 Flow Specification Traffic Filtering Action changes

   One of the traffic filtering actions which can be expressed by BGP
   extended community is defined in [RFC5575] as traffic-marking.  This
   extended community type is of value: 0x8009.

   For the purpose of making it compatible with IPv6 header action
   expressed by presence of this extended community has been modified to
   read:

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   Traffic Marking: The traffic marking extended community instructs a
   system to modify first 6 bits of Traffic Class field as (recommended
   by [RFC2474]) of a transiting IPv6 packet to the corresponding value.
   This extended community is encoded as a sequence of 42 zero bits
   followed by the 6 bits overwriting DSCP portion of Traffic Class
   value.

   Another traffic filtering action defined in [RFC5575] as a BGP
   extended community is redirect.  To allow an IPv6 address specific
   route-target, a new traffic action IPv6 address specific extended
   community is provided.  The extended community type has the value
   0x800b.

   Redirect-IPv6: The redirect IPv6 address specific extended community
   allows the traffic to be redirected to a VRF routing instance that
   lists the specified IPv6 address specific route-target in its import
   policy.  If several local instances match this criteria, the choice
   between them is a local matter (for example, the instance with the
   lowest Route Distinguisher value can be elected).  This extended
   community uses the same encoding as the IPv6 address specific Route
   Target extended community [RFC5701].

5.  Security considerations

   No new security issues are introduced to the BGP protocol by this
   specification.

6.  IANA Considerations

   IANA is requested to rename currently defined SAFI 133 and SAFI 134
   per [RFC5575] to read:

   133     Dissemination of flow specification rules
   134     L3VPN dissemination of flow specification rules

   IANA is requested to create and maintain a new registry entitled:
   "Flow Spec IPv6 Component Types".  The following component types have
   been registered:

   Type 1 - Destination IPv6 Prefix
   Type 2 - Source IPv6 Prefix
   Type 3 - Next Header
   Type 4 - Port
   Type 5 - Destination port
   Type 6 - Source port
   Type 7 - ICMP type
   Type 8 - ICMP code
   Type 9 - TCP flags

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   Type 10 - Packet length
   Type 11 - DSCP
   Type 12 - Fragment
   Type 13 - Flow Label
   Type 14 - Traffic Class

7.  Acknowledgments

   Authors would like to thank Pedro Marques, Hannes Gredler and Bruno
   Rijsman, Brian Carpenter, and Thomas Mangin for their valuable input.

8.  References

8.1.  Normative References

   [I-D.ietf-6man-flow-3697bis]
              Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme,
              "IPv6 Flow Label Specification", draft-ietf-6man-flow-
              3697bis-07 (work in progress), July 2011.

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

   [RFC2460]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", RFC 2460, December 1998.

   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474, December
              1998.

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC5492]  Scudder, J. and R. Chandra, "Capabilities Advertisement
              with BGP-4", RFC 5492, February 2009.

   [RFC5575]  Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
              and D. McPherson, "Dissemination of Flow Specification
              Rules", RFC 5575, August 2009.

   [RFC5701]  Rekhter, Y., "IPv6 Address Specific BGP Extended Community
              Attribute", RFC 5701, November 2009.

8.2.  Informative References

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   [RFC5095]  Abley, J., Savola, P., and G. Neville-Neil, "Deprecation
              of Type 0 Routing Headers in IPv6", RFC 5095, December
              2007.

Authors' Addresses

   Robert Raszuk (editor)
   NTT MCL Inc.
   101 S Ellsworth Avenue Suite 350
   San Mateo, CA  94401
   US

   Email: robert@raszuk.net

   Burjiz Pithawala
   Cisco Systems
   170 West Tasman Drive
   San Jose, CA  95134
   US

   Email: bpithaw@cisco.com

   Danny McPherson
   Verisign, Inc.

   Email: dmcpherson@verisign.com

   Andy Karch
   Cisco Systems
   170 West Tasman Drive
   San Jose, CA  95134
   US

   Email: akarch@cisco.com

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