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Versions: 00

Network Working Group                                              Z. Li
Internet-Draft                                                 S. Zhuang
Intended status: Standards Track                                   N. Wu
Expires: September 22, 2016                          Huawei Technologies
                                                          March 21, 2016


         BGP FlowSpec Redirect to Generalized Segment ID Action
           draft-li-idr-flowspec-redirect-generalized-sid-00

Abstract

   This document defines a new type of the redirect extended community,
   called as Redirect to Generalized Segment ID Extended Community.
   When activated, the Redirect to Generalized Segment ID Extended
   Community is used by BGP FlowSpec Controller to signal the specific
   redirecting action to BGP Flowspec Client, and then the BGP Flowspec
   Client will use the Generalized Segment ID and the Segment Type to
   find a local forwarding entity in a local mapping table.

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 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 September 22, 2016.

Copyright Notice

   Copyright (c) 2016 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
   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.  Definitions and Acronyms  . . . . . . . . . . . . . . . . . .   3
   3.  Redirect to Generalized Segment ID Extended Community . . . .   3
   4.  Using Redirect to Generalized Segment ID Extended Community .   5
   5.  Validation Procedures . . . . . . . . . . . . . . . . . . . .   6
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   Segment Routing [I-D.ietf-spring-segment-routing] for unicast traffic
   has been proposed to cope with the usecases in traffic engineering,
   fast re-reroute, service chain, etc.  Segment Path Programming (SPP)
   [I-D.li-spring-segment-path-programming] generalizes more use cases
   based on segment and proposes the concept of Segment Path
   Programming.  In the field of Segment Path Programming: 1.  The
   Segment used in the programmed segment path is not only used in the
   forwarding plane, but also used in the control plane. 2.  The
   programmed segment path is not only used in the transport layer, but
   also used in the service layer.

   [RFC5575] defines the flow specification (FlowSpec) that allows to
   convey flow specifications and traffic Action/Rules associated (rate-
   limiting, redirect, remark ...).  BGP Flow specifications are encoded
   within the MP_REACH_NLRI and MP_UNREACH_NLRI attributes.  Rules
   (Actions associated) are encoded in Extended Community attribute.
   The BGP Flow Specification function allows BGP Flow Specification
   routes that carry traffic policies to be transmitted to BGP Flow
   Specification peers to control attack traffic.

   Now the drafts of BGP Flowspec for redirecting to VRF/IP/Tunnel keep
   the traditional way to extend BGP FlowSpec to redirect to an entity




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   with explicit meaning which has been defined clearly in the existing
   work.

   We can reuse some work of segment routing and generalize the concept
   of Segment, and then it can provide a base for the abstracted view of
   different forwarding entities.  Since now segment ID can be the
   indicator of interface, node, tunnel, if we do not map segment ID to
   MPLS label or IPv6 address, it can be an identifier of all kinds of
   forwarding entities in the control plane which can be used outside.

   This document defines a new type of the redirect extended community,
   called as Redirect to Generalized Segment ID Extended Community.
   When activated, the Redirect to Generalized Segment ID Extended
   Community is used by BGP FlowSpec Controller to signal the specific
   redirecting action to BGP Flowspec Client, and then the BGP Flowspec
   Client will use the Generalized Segment ID and Segment Type to find a
   local forwarding entity in a local mapping table.

   Existing technologies (BGP, IGP, LDP, SR, RSVP, Manual-Config, etc...
   ) can be used to setup the mapping tables per segment type.

2.  Definitions and Acronyms

   o  FS: Flow Specification

   o  SR: Segment Routing

   o  SID: Segment Identifier

   o  GSID: Generalized Segment ID

   o  SPP: Segment Path Programming

3.  Redirect to Generalized Segment ID Extended Community

   This document defines a new type of the redirect extended community,
   called as Redirect to Generalized Segment ID Extended Community.
   This extended community is a new transitive extended community with
   the Type is TBD1 and the Sub-Type field is TBD2.

   This document defines the following Redirect to Generalized Segment
   ID Extended Community:









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   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | Type=TBD1     | Sub-Type=TBD2 | Flags(1 octet)| Segment Type  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                  Generalized Segment ID                       |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

  Figure 1: Redirect to Generalized Segment ID Extended Community Format

   Where:

   Type: 1 octet, to be assigned by IANA

   Sub-Type: 1 octet, to be assigned by IANA

   Flags: 1 octet field, TBD

   Segment Type: 1 octet, Per [I-D.li-spring-segment-path-programming],
   the Segment Type includes:

   o  1 - Node Segment

   o  2 - Agency Segment

   o  3 - AS (Autonomous System) Segment

   o  4 - Anycast Segment

   o  5 - Multicast Segment

   o  6 - Tunnel Segment (Tunnel Binding Segment )

   o  7 - VPN Segment

   o  8 - OAM Segment

   o  9 - ECMP (Equal Cost Multi-Path) Segment

   o  10 - QoS Segment

   o  11 - Bandwidth-Guarantee Segment

   o  12 - Security Segment

   o  13 - Multi-Topology Segment

   o  etc.




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   Generalized Segment ID: 4 octets, it can be used to find a local
   forwarding entity in the mapping table designated by the Segment
   Type.

4.  Using Redirect to Generalized Segment ID Extended Community

   In the transport layers, there can be multiple tunnels with different
   constraints to one specific destination.  In the traditional way, the
   tunnel is set up by the distributed forwarding nodes.  As the PCE-
   initiated LSP setup [I-D.ietf-pce-pce-initiated-lsp]is introduced,
   the tunnel setup can be triggered by the central controlled way.  In
   order to satisfy the different service requirements, it is necessary
   to provide the capability to flexibly map the service to different
   tunnels.  Since the central control point has enough information
   based on the whole network view, it can be an effective way to map
   the service to the tunnel by the central point and advertise the
   mapping information to the end-points of the service to guide the
   mapping in the forwarding node.

   The method to implement mapping service to tunnels can directly
   introduce the tunnel attribute to specify the tunnel proposed by [I-
   D.li-idr-mpls-path-programming].  [I-D.li-spring-tunnel-segment]
   proposes one new type of segment, Tunnel Segment, which can provide
   an alternative way to implement mapping service to tunnels.  In the
   following figure, the central controller can trigger to set up the
   MPLS TE tunnels through PCE-initiated LSP and allocate Segment ID for
   the tunnel in the Node-1.

          +------------+
          |  Central   |
          | Controller |
          +------------+
             ^ Tunnel Binding
             | SID (Z)
             |          .-----.
             |         (       )
             V     .--(         )--.
       +-------+  (                 )  +-------+
       |       |_(  IP/MPLS Network  )_|       |
       |Node-1 | ( ================> ) |Node-2 |
       +-------+  (MPLS TE/IP Tunnel)  +-------+
                   '--(         )--'
                       (       )
                        '-----'

       Figure 2: Using Tunnel Segment for Mapping Service to Tunnel





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   The central controller can send a flowspec route to Node-1 with a
   'Redirect to Generalized Segment ID' Extended Community to map a
   specfic service to the tunnel segment identified by the Segment Type
   and Generalized Segment ID.

   When Node-1 receives a flowspec route with a 'Redirect to Generalized
   Segment ID' Extended Community.  It installs a traffic filtering rule
   that matches the packets described by the NLRI field and redirects
   them to the tunnel with the Generalized Segment ID.

5.  Validation Procedures

   The validation check described in [RFC 5575] and revised in
   [I-D.ietf-idr-bgp-flowspec-oid] SHOULD be applied by default to
   received flowspec routes with a Redirect to Generalized Segment ID
   Extended Community.  This means that a flowspec route with a
   destination prefix subcomponent SHOULD NOT be accepted from an EBGP
   peer unless that peer also advertised the best path for the matching
   unicast route.

6.  IANA Considerations

   TBD.

7.  Security Considerations

   TBD.

8.  Acknowledgements

   TBD.

9.  References

   [I-D.ietf-idr-bgp-flowspec-oid]
              Uttaro, J., Filsfils, C., Smith, D., Alcaide, J., and P.
              Mohapatra, "Revised Validation Procedure for BGP Flow
              Specifications", draft-ietf-idr-bgp-flowspec-oid-03 (work
              in progress), March 2016.

   [I-D.ietf-isis-segment-routing-extensions]
              Previdi, S., Filsfils, C., Bashandy, A., Gredler, H.,
              Litkowski, S., Decraene, B., and J. Tantsura, "IS-IS
              Extensions for Segment Routing", draft-ietf-isis-segment-
              routing-extensions-06 (work in progress), December 2015.






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   [I-D.ietf-spring-segment-routing]
              Filsfils, C., Previdi, S., Decraene, B., Litkowski, S.,
              and R. Shakir, "Segment Routing Architecture", draft-ietf-
              spring-segment-routing-07 (work in progress), December
              2015.

   [I-D.li-spring-segment-path-programming]
              Li, Z. and I. Milojevic, "Segment Path Programming (SPP)",
              draft-li-spring-segment-path-programming-00 (work in
              progress), October 2015.

   [I-D.li-spring-tunnel-segment]
              Li, Z. and N. Wu, "Tunnel Segment in Segment Routing",
              draft-li-spring-tunnel-segment-01 (work in progress),
              March 2016.

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

   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <http://www.rfc-editor.org/info/rfc4271>.

   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760,
              DOI 10.17487/RFC4760, January 2007,
              <http://www.rfc-editor.org/info/rfc4760>.

   [RFC5492]  Scudder, J. and R. Chandra, "Capabilities Advertisement
              with BGP-4", RFC 5492, DOI 10.17487/RFC5492, February
              2009, <http://www.rfc-editor.org/info/rfc5492>.

   [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,
              <http://www.rfc-editor.org/info/rfc5575>.

Authors' Addresses










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   Zhenbin Li
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: lizhenbin@huawei.com


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

   Email: zhuangshunwan@huawei.com


   Nan Wu
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: eric.wu@huawei.com


























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