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Versions: (draft-hao-idr-flowspec-evpn) 00 01 02 03 04 05 06 07 08 09 10 11

Network Working Group                                             W. Hao
Internet-Draft                                               D. Eastlake
Intended status: Standards Track                                  Huawei
Expires: July 7, 2019                                          J. Uttaro
                                                                    AT&T
                                                            S. Litkowski
                                                 Orange Business Service
                                                               S. Zhuang
                                                                  Huawei
                                                        January 03, 2019


          BGP Dissemination of L2VPN Flow Specification Rules
                    draft-ietf-idr-flowspec-l2vpn-09

Abstract

   This document defines a BGP flow-spec extension to disseminate L2 VPN
   Ethernet traffic filtering rules.  SAFI=134 in [RFC5575] is redefined
   for this purpose.  A new subset of component types and extended
   community also are defined.  A new subset of component types and new
   extended community also are defined.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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 https://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 July 7, 2019.






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Copyright Notice

   Copyright (c) 2019 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
   (https://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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Layer 2 Flow Specification encoding in BGP  . . . . . . . . .   3
   3.  Ethernet Flow Specification encoding in BGP . . . . . . . . .   4
     3.1.  Order of Traffic Filtering Rules  . . . . . . . . . . . .   6
   4.  Ethernet Flow Specification Traffic Actions . . . . . . . . .   7
     4.1.  VLAN-action . . . . . . . . . . . . . . . . . . . . . . .   8
     4.2.  TPID-action . . . . . . . . . . . . . . . . . . . . . . .   9
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  11
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   BGP Flow-spec is an extension to BGP that supports the dissemination
   of traffic flow specification rules.  It leverages the BGP Control
   Plane to simplify the distribution of ACLs.  Using this extension new
   filter rules can be injected to all BGP peers simultaneously without
   changing router configuration.  The typical application of BGP Flow-
   spec is to automate the distribution of traffic filter lists to
   routers for DDOS mitigation, access control, etc.

   [RFC5575] defines a new BGP Network Layer Reachability
   Information(NLRI) format used to distribute traffic flow
   specification rules.  NLRI (AFI=1, SAFI=133) is for IPv4 unicast
   filtering.  NLRI (AFI=1, SAFI=134) is for BGP/MPLS VPN filtering.
   The Flow specification match part only includes L3/L4 information



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   like source/destination prefix, protocol, ports, and etc., so traffic
   flows can only be selectively filtered based on L3/L4 information.

   Layer 2 Virtual Private Networks (L2VPNs) have already been deployed
   in an increasing number of networks today.  In L2VPN network, we also
   have requirement to deploy BGP Flow-spec to mitigate DDoS attack
   traffic.  Within L2VPN network, both IP and non-IP Ethernet traffic
   maybe exist.  For IP traffic filtering, the Flow specification rules
   defined in [RFC5575] which include match criteria and actions can
   still be used, flow specification rules received via new NLRI format
   apply only to traffic that belongs to the VPN instance(s) in which it
   is imported.  For non-IP Ethernet traffic filtering, Layer 2 related
   information like source/destination MAC and VLAN should be
   considered.  But the flow specification match criteria defined in
   [RFC5575] only include layer 3 and layer 4 IP information, not layer
   2 Ethernet information.

   There are different kinds of L2VPN networks like EVPN [RFC7432], BGP
   VPLS [RFC4761], LDP VPLS [RFC4762] and border gateway protocol (BGP)
   auto discovery [RFC6074].  Because the flow-spec feature relies on
   BGP protocol to distribute traffic filtering rules, it can only be
   incrementally deployed in those L2VPN networks where BGP has already
   been used for auto discovery and/or signaling purposes such as BGP-
   based VPLS [RFC4761], EVPN and LDP-based VPLS [RFC4762] [4762] with
   BGP auto-discovery [RFC6074].

   This draft proposes a new subset of flow-spec component types and an
   extended community to support L2VPN flow-spec application.  The flow-
   spec rules can be enforced on all border routers or on some interface
   sets of the border routers.  SAFI=134 in [RFC5575] is redefined for
   dissemination of traffic filtering information in an L2VPN
   environment.

2.  Layer 2 Flow Specification encoding in BGP

   The [RFC5575] defines SAFI 133 and SAFI 134 for "dissemination of
   IPv4 flow specification rules" and "dissemination of VPNv4 flow
   specification rules" respectively.  [I-D.ietf-idr-flow-spec-v6]
   redefines the [RFC5575] SAFIs in order to make them applicable to
   both IPv4 and IPv6 applications.  This document will further redefine
   the SAFI 134 in order to make them applicable to L2VPN applications.

   The following changes are defined:

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




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   For SAFI 134 the indication to which address family it is referring
   to will be recognized by AFI value (AFI=1 for VPNv4, AFI=2 VPNv6 and
   AFI=25 for L2VPN).  Such modification is fully backwards compatible
   with existing implementation and production deployments.

   For SAFI 134 the indication to which address family it is referring
   to will be recognized by AFI value (AFI=1 for VPNv4, AFI=2 VPNv6 and
   AFI=25 for L2VPN).  Such modification is fully backwards compatible
   with existing implementation and production deployments.

3.  Ethernet Flow Specification encoding in BGP

   The NLRI format for this address family consists of a fixed-length
   Route Distinguisher field (8 bytes) followed by a flow specification,
   following the encoding defined in this document.  The NLRI length
   field includes both the 8 bytes of the Route Distinguisher as well as
   the subsequent flow specification.

   Flow specification rules received via this NLRI apply only to traffic
   that belongs to the VPN instance(s) into which it is imported.  Flow
   rules are accepted by default when received from remote PE routers.

   Besides the component types defined in [RFC5575] and
   [I-D.ietf-idr-flow-spec-v6], this document specifies the following
   additional component types for L2 VPN Ethernet traffic filtering:

   Type 14 - Ethernet Type

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

   Defines a list of {operation, value} pairs used to match two-octet
   field.  Values are encoded as 2-byte quantities.  Ethernet II framing
   defines the two-octet Ethernet Type (EtherType) field in an Ethernet
   frame, preceded by destination and source MAC addresses, that
   identifies an upper layer protocol encapsulating the frame data.

   Type 15 - Source MAC

   Encoding: <type (1 octet), MAC Address length (1 octet), MAC Address>
   Defines the source MAC Address to match.

   Type 16 - Destination MAC

   Encoding: <type (1 octet), MAC Address length (1 octet), MAC Address>
   Defines the destination MAC Address to match.

   Type 17 - DSAP(Destination Service Access Point) in LLC




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

   Defines a list of {operation, value} pairs used to match the 1-octet
   DSAP in the 802.2 LLC (Logical Link Control Header).  Values are
   encoded as 1-byte quantities.  The operation field is encoded as a
   'Numeric operator' defined in [RFC5575].

   Type 18 - SSAP(Source Service Access Point) in LLC

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

   Defines a list of {operation, value} pairs used to match the 1-octet
   SSAP in the 802.2 LLC.  Values are encoded as 1-byte quantities.

   Type 19 - Control field in LLC

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

   Defines a list of {operation, value} pairs used to match 1-octet
   control field in the 802.2 LLC.  Values are encoded as 1-byte
   quantities.

   Type 20 - SNAP

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

   Defines a list of {operation, value} pairs used to match 5-octet SNAP
   (Sub-Network Access Protocol) field.  Values are encoded as 5-byte
   quantities.

   Type 21 - VLAN ID

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

   Defines a list of {operation, value} pairs used to match VLAN ID.
   Values are encoded as 2-byte quantities, where the four most
   significant bits are zero and the 12 least significant bits contain
   the VLAN value.

   In the virtual local-area network (VLAN) stacking case, the VLAN ID
   is the outer VLAN ID.

   Type 22 - VLAN COS

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

   Defines a list of {operation, value} pairs used to match 3-bit VLAN
   COS fields [802.1Q].  Values are encoded using a single byte, where



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   the five most significant bits are zero and the three least
   significant bits contain the VLAN COS value.

   In the virtual local-area network (VLAN) stacking case, the VLAN COS
   is outer VLAN COS.

   Type 23 - Inner VLAN ID

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

   Defines a list of {operation, value} pairs used to match the inner
   VLAN ID using for virtual local-area network (VLAN) stacking or Q in
   Q use.  Values are encoded as 2-byte quantities, where the four most
   significant bits are zero and the 12 least significant bits contain
   the VLAN value.

   In single VLAN case, this component type MUST NOT be used.

   Type 24 - Inner VLAN COS

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

   Defines a list of {operation, value} pairs used to match 3-bit inner
   VLAN COS fields [802.1Q] using for virtual local-area network (VLAN)
   stacking or Q in Q use.  Values are encoded using a single byte,
   where the five most significant bits are zero and the three least
   significant bits contain the VLAN COS value.

   In single VLAN case, the component type MUST not be used.

3.1.  Order of Traffic Filtering Rules

   The original definition for the order of traffic filtering rules can
   be reused with new consideration for the MAC Address 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
   lowest offset has precedence, as this flow matches the most
   significant bit.













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   Pseudocode:
   flow_rule_L2_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) == MAC_DESTINATION || MAC_SOURCE) {
               common = MIN(MAC Address length (comp1),
                        MAC Address length (comp2));
               cmp = MAC Address compare(comp1, comp2, common);
               // 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.  Ethernet Flow Specification Traffic Actions

   The default action for a layer 2 traffic filtering flow specification
   is to accept traffic that matches that particular rule.  The
   following extended community values per [RFC5575] can be used to
   specify particular actions in an L2 VPN network:

   +--------+--------------------+--------------------------+
   |  type  | extended community |        encoding          |
   +--------+--------------------+--------------------------+
   | 0x8006 | traffic-rate       | 2-byte as#, 4-byte float |
   | 0x8007 | traffic-action     | bitmask                  |
   | 0x8008 | redirect           | 6-byte Route Target      |
   | 0x8009 | traffic-marking    | DSCP value               |
   +--------+--------------------+--------------------------+




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   Redirect: The action should be redefined to allow the traffic to be
   redirected to a MAC or IP VRF routing instance that lists the
   specified route-target in its import policy.

   Besides the above extended communities, this document also proposes
   the following BGP extended communities specifications for Ethernet
   flow to extend [RFC5575]:

   +--------+------------------------+--------------------------+
   | type   | extended community     |   encoding               |
   +--------+------------------------+--------------------------+
   |  TBD1  | VLAN-action            |   bitmask                |
   |  TBD2  | TPID-action            |   bitmask                |
   +--------+------------------------+--------------------------+


4.1.  VLAN-action

   The VLAN-action extended community, as shown in the diagram below,
   consists of 6 bytes that include t action Flags, two VLAN IDs, and
   the associating COS value.  The action Flags fields are further
   divided into two parts which correspond to the first action and the
   second action respectively, bit 0 to bit 7 give the first action
   while bit 8 to bit 15 give the second action.  The bits of PO, PU,
   SW, RI and RO in each part represent the action of Pop, Push, Swap,
   Rewrite inner VLAN and Rewrite outer VLAN respectively.  Through this
   method, more complicated actions also can be represented in a single
   VLAN-action extened community, such as SwapPop, PushSwap, etc.  For
   example, SwapPop action is the sequence of two actions, the first
   action is Swap and the second action is Pop.

   0                       7                       15
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   |PO1|PU1|SW1|RI1|RO1|...|PO2|PU2|SW2|RI2|RO2|...|
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   | VLAN ID1                          |COS1    |R1|
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   | VLAN ID2                          |COS2    |R2|
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+


   PO1: Pop action.  If the PO1 flag is one, it indicates the outmost
   VLAN should be removed.

   PU1: Push action.  If PU1 is one, it indicates VLAN ID1 will be
   added, the associated COS is COS1.





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   SW1: Swap action.  If the SW1 flag is one, it indicates the outer
   VLAN and inner VLAN should be swapped.

   PO2: Pop action.  If the PO2 flag is one, it indicates the outmost
   VLAN should be removed.

   PU2: Push action.  If PU2 is one, it indicates VLAN ID2 will be
   added, the associated COS is COS2.

   SW2: Swap action.  If the SW2 flag is one, it indicates the outer
   VLAN and inner VLAN should be swapped.

   RI1 and RI2: Rewrite inner VLAN action.  If the RI flag is one, it
   indicates the inner VLAN should be replaced by a new VLAN, the new
   VLAN is VLAN ID1, the associated COS is COS1.  If the VLAN ID1 is 0,
   the action is to only modify the COS value of inner VLAN.

   RO1 and RO2: Rewrite outer VLAN action.  If the RO flag is one, it
   indicates the outer VLAN should be replaced by a new VLAN, the new
   VLAN is VLAN ID2, the associated COS is COS2.  If the VLAN ID2 is 0,
   the action is to only modify the COS value of outer VLAN.

   R1 and R2: Reserved for future use.  MUST be sent as zero and ignored
   on receipt.

   Giving an example, if the action of PUSH Inner VLAN 10 with COS value
   5 and Outer VLAN 20 with COS value 6 is needed, the format of the
   VLAN-action extended community is as follows:

     0                    7                      15
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   |0 |1 |0 |0 |0 |0 |0 |0 |0 |1 |0 |0 |0 |0 |0 |0 |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   | 10                                |1 |0 |1 |0 |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   | 20                                |1 |1 |0 |0 |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+


4.2.  TPID-action

   The TPID-action extended community consists of 6 bytes which includes
   the fields of action Flags, TPID1 and TPID2.








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     0                                           15
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   |TI|TO|                     Resv                |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   |                    TP ID1                     |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
   |                    TP ID2                     |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+


   TI: Mapping inner TP ID action.  If the TI flag is one, it indicates
   the inner TP ID should be replaced by a new TP ID, the new TP ID is
   TP ID1.

   TO: Mapping outer TP ID action.  If the TO flag is one, it indicates
   the outer TP ID should be replaced by a new TP ID, the new TP ID is
   TP ID2.

   Resv: Reserved for future use.  MUST be sent as zero and ignored on
   receipt.

5.  IANA Considerations

   IANA is requested to change the description for SAFI 134 [RFC5575]
   [RFC5575] to read as follows more general description and to change
   the reference for it to [this document]:

   134 VPN dissemination of flow specification rules

   IANA is requested to allocate 11 new values in the Flow-Spec
   Component Type registry as follows:

   +--------+-------------------------------+--------------------------+
   |  type  |         RFC or Draft          |       discription        |
   +--------+-------------------------------+--------------------------+
   |   14   |This draft                     | Ethernet Type            |
   |   15   |This draft                     | Source MAC               |
   |   16   |This draft                     | Destination MAC          |
   |   17   |This draft                     | DSAP in LLC              |
   |   18   |This draft                     | SSAP in LLC              |
   |   19   |This draft                     | Control field in LLC     |
   |   20   |This draft                     | SNAP                     |
   |   21   |This draft                     | VLAN ID                  |
   |   22   |This draft                     | VLAN COS                 |
   |   23   |This draft                     | Inner VLAN ID            |
   |   24   |This draft                     | Inner VLAN COS           |
   +--------+-------------------------------+--------------------------+




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   IANA is requested to update the reference for the following
   assignment in the "BGP Extended Communities Type - extended,
   transitive" registry:

   Type value Name Reference

   ---------- ---------------------------------------- ---------

   0x080A Flow spec VLAN action [this document]

   0x080B Flow spec TPID action [this document]

6.  Security Considerations

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

7.  Acknowledgements

   The authors wish to acknowledge the important contributions of Hannes
   Gredler, Xiaohu Xu, Zhenbin Li, Lucy Yong and Feng Dong.

8.  Contributors

   Qiandeng Liang

   Huawei Technologies

   101 Software Avenue, Yuhuatai District

   Nanjing 210012

   China

   Email: liangqiandeng@huawei.com

9.  References

9.1.  Normative References

   [I-D.ietf-idr-flow-spec-v6]
              McPherson, D., Raszuk, R., Pithawala, B.,
              akarch@cisco.com, a., and S. Hares, "Dissemination of Flow
              Specification Rules for IPv6", draft-ietf-idr-flow-spec-
              v6-09 (work in progress), November 2017.






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   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC4761]  Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
              LAN Service (VPLS) Using BGP for Auto-Discovery and
              Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
              <https://www.rfc-editor.org/info/rfc4761>.

   [RFC4762]  Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
              LAN Service (VPLS) Using Label Distribution Protocol (LDP)
              Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
              <https://www.rfc-editor.org/info/rfc4762>.

   [RFC5575]  Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
              and D. McPherson, "Dissemination of Flow Specification
              Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
              <https://www.rfc-editor.org/info/rfc5575>.

   [RFC6074]  Rosen, E., Davie, B., Radoaca, V., and W. Luo,
              "Provisioning, Auto-Discovery, and Signaling in Layer 2
              Virtual Private Networks (L2VPNs)", RFC 6074,
              DOI 10.17487/RFC6074, January 2011,
              <https://www.rfc-editor.org/info/rfc6074>.

9.2.  Informative References

   [RFC7432]  Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
              Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
              Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
              2015, <https://www.rfc-editor.org/info/rfc7432>.

Authors' Addresses

   Weiguo Hao
   Huawei
   101 Software Avenue,
   Nanjing  210012
   China

   Email: haoweiguo@huawei.com









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   Donald E. Eastlake, 3rd
   Huawei
   155 Beaver Street
   Milford, MA   01757
   USA

   Email: d3e3e3@gmail.com


   James Uttaro
   AT&T

   Email: uttaro@att.com


   Stephane Litkowski
   Orange Business Service

   Email: stephane.litkowski@orange.com


   Shunwan Zhuang
   Huawei
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: zhuangshunwan@huawei.com























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