INTERNET-DRAFT                                           Donald Eastlake
Intended Status: Proposed Standard                            Weiguo Hao
                                                          Shunwan Zhuang
                                                              Zhenbin Li
                                                     Huawei Technologies
                                                                 Rong Gu
                                                             China Mobil
Expires: March 10, 2019                               September 11, 2018

                          BGP Dissemination of
Network Virtualization Overlays (NVO3) Flow Specification Rules

   This draft specifies a new subset of component types to support the
   (Network Virtualization Overlays (NVO3)) flow-spec application.

Status of This Document

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

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INTERNET-DRAFT                                        NVO3 BGP Flow-Spec

Table of Contents

      1. Introduction............................................3
      1.1 Terminology............................................5

      2. NVO3 Flow Specification Encoding........................6

      3. NVO3 Flow Specification Traffic Actions.................8
      4. Security Considerations.................................8
      5. IANA Considerations.....................................8

      Normative References.......................................9
      Informative References.....................................9

      Authors' Addresses........................................10

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1. Introduction

   BGP Flow-spec is an extension to BGP that supports the dissemination
   of traffic flow specification rules.  It uses the BGP Control Plane
   to simplify the distribution of Access Control Lists (ACLs) and
   allows new filter rules to be injected to all BGP peers
   simultaneously without changing router configuration. A typical
   application of BGP Flow-spec is to automate the distribution of
   traffic filter lists to routers for Distributed Denial of Service
   (DDOS) mitigation.

   [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. [IPv6-FlowSpec] and [Layer2-
   FlowSpec] extend the flow-spec rules for IPv6 and layer 2 Ethernet
   packets respectively. All these previous flow specifications match
   only single layer IP/Ethernet information fields like
   source/destination MAC, source/destination IP prefix, protocol type,
   ports, and the like.

   In the cloud computing era, multi-tenancy has become a core
   requirement for data centers. Since Network Virtualization Overlays
   (NVO3) can satisfy multi-tenancy key requirements, this technology is
   being deployed in an increasing number of cloud data center networks.
   NVO3 is an overlay technology and VXLAN [RFC7348] and NVGRE [RFC7367]
   are two typical NVO3 encapsulations. GENEVE [GENEVE], GUE [GUE] and
   GPE [GPE] are three emerging NVO3 encapsulations. Because it is an
   overlay technology involving an additional level of encapsulation,
   flow specification matching on the inner header as well as the outer
   header, as specified below, is needed.

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                          +----| PE |----+
              +---------+ |    +----+    | +---------+
      +----+  |        +---+            +---+        |  +----+
      |NVE1|--|        |   |            |   |        |--|NVE3|
      +----+  |        |GW1|            |GW3|        |  +----+
              |        +---+            +---+        |
              |  NVO-1   |      MPLS      |   NVO-2  |
              |        +---+            +---+        |
              |        |   |            |   |        |
      +----+  |        |GW2|            |GW4|        |  +----+
      |NVE2|--|        +---+            +---+        |--|NVE4|
      +----+  +---------+ |              | +---------+  +----+

                Figure 1. NVO3 Data Center Interconnection

   The MPLS L2/L3 VPN in the WAN network can be used for NVO3 based data
   center network interconnection. When the Data Center (DC) and the WAN
   are operated by the same administrative entity, the Service Provider
   can decide to integrate the gateway (GW) and WAN Edge PE functions in
   the same router for capital and operational cost saving reasons. This
   is illustrated in Figure 1. There are two interconnection solutions
   as follows:

   1. End-to-end NVO3 tunnel across different data centers: NVE1 perform
      NVO3 encapsulation for DC interconnection with NVE3, the
      destination VTEP IP is NVE3's IP. The GW doesn't perform NVO3
      tunnel termination.  The DC interconnect WAN is pure an underlay

   2. Segmented NVO3 tunnels across different data centers: NVE1 doesn't
      perform end-to-end NVO3 encapsulation to NVE3 for DC
      interconnection.  The GW performs NVO3 tunnel encapsulation
      termination, and then transmits the inner original traffic through
      MPLS network to the peer data center GW. The peer data center GW
      again terminates MPLS encapsulation, and then performs NVO3
      encapsulation to transmit the traffic to the local NVE3.

   In the first solution, to differentiate bandwidth and Quality of
   Service (QoS) among different tenants or applications, different TE
   tunnels in the WAN network will be used to carry the end-to-end NVO3
   encapsulation traffic using VN ID, NVO3 outer header DSCP, and other
   fields as the traffic classification match part. The BGP Flow-spec
   protocol can be used to set the traffic classification on all GWs

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   In the second solution, a centralized BGP speaker can be deployed for
   DDOS mitigation in the WAN network. When the analyzer detects
   abnormal traffic, it will automatically generate Flow-spec rules and
   distribute them to each GW through BGP Flow-spec protocol, the match
   part should include matching on inner or outer L2/L3 layer or NVO3

   In summary, the Flow specification match part on the GW/PE should be
   able to include inner layer 2 Ethernet header, inner layer 3 IP
   header, outer layer 2 Ethernet header, outer layer 3 IP header,
   and/or NVO3 header information. Because the current flow-spec
   matching facilities lack a layer indicator and NVO3 header
   information, those facilities can't be used directly for traffic
   filtering based on NVO3 headers or on a specified layer header
   directly. This draft specifies a new subset of component types to
   support the NVO3 flow-spec application.

1.1 Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   The reader is assumed to be familiar with BGP and NVO3 terminology.
   The following terms and acronyms are used in this document with the
   meaning indicated:

   ACL - Access Control List

   DC - Data Center

   DDOS - Distributed Denial of Service (Attack).

   GW - gateway

   VN - virtual network

   VTEP - Virtual Tunnel End Point

   WAN - wide area network

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2. NVO3 Flow Specification Encoding

   The current Flow-spec rules can only recognize flows based on the
   outer layer header of NVO3 encapsulation data packets. To enable
   traffic filtering based on an NVO3 header and on an inner header of
   NVO3 packets, a new component type acting as a delimiter is
   introduced. The delimiter type is used to indicate the boundary
   between the inner and outer layer component types for NVO3 data
   packets. All the component types defined in [RFC5575],
   [IPv6-FlowSpec], [Layer2-FlowSpec], and the like can be used for the
   inner or outer header as indicated by the use of delimiters.

   Because the NVO3 outer layer address normally belongs to a public
   network, the "Flow Specification" NLRI for the outer layer header
   doesn't need to include a Route Distinguisher field (8 bytes). If the
   outer layer address belongs to a VPN, the NLRI format for the outer
   header should consist of a fixed-length Route Distinguisher field (8
   bytes) corresponding to the VPN. This Route Distinguisher is followed
   by the detail flow specifications for the outer layer.

   The VN ID is the identification for each tenant network. The "Flow
   Specification" NLRI for an NVO3 header part should always include the
   VN ID field but a Route Distinguisher field doesn't need to be

   The inner layer MAC/IP address is always associated with a VN ID.
   Thus the NLRI format for the inner header should consist of a fixed-
   length VN ID field (4 bytes). The VN ID is followed by the detailed
   flow specifications for the inner layer. The NLRI length field shall
   include both the 4 bytes of the VN ID as well as the subsequent flow
   specification. In the NVO3 terminating into a VPN scenario, if
   multiple access VN IDs map to one VPN instance, one shared VN ID can
   be carried in the Flow-Spec rule to enforce the rule on the entire
   VPN instance and the shared VN ID and VPN correspondence should be
   configured on each VPN PE beforehand. In this case, the function of
   the layer3 VN ID is the same as a Route Distinguisher: it acts as the
   identification of the VPN instance.

   This document specifies the following Flow-Spec Component Types for
   use with NVO3 flows:

   Type TBD1 - Delimiter type
      Encoding: <type (1 octet), length (1 octet), Value>.

         When this delimiter type is present, it indicates the component
         types and layer for the NVO3 header fields immediately
         following. At the same time, it indicates the end of the
         component types belonging to the previous delimiter.

         The value field defines encapsulation type and is encoded as:

D. Eastlake, et al                                              [Page 6]

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                        | 0   1   2   3   4   5   6   7 |
                        |          Encap Type           |
                        | I | O |        Resv           |

         This document defines the following Encap types:

            - VXLAN: Tunnel Type = 0

            - NVGRE: Tunnel Type = 1

         I: If I is set to one, it indicates the component types for the
         inner layer of NVO3 headers immediately follow.

         O: If O is set to one, it indicates the component types for the
         outer layer of NVO3 headers immediately follow.

For NVO3 header part, the following additional component types are

Type TBD2 - VN ID

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

      Defines a list of {operation, value} pairs used to match the
      24-bit VN ID that is used as the tenant identification in NVO3
      networks. For NVGRE encapsulation, the VN ID is equivalent to
      VSID. Values are encoded as 1- to 3-byte quantities.

Type TBD3 - Flow ID

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

      Defines a list of {operation, value} pairs used to match 8-bit
      Flow ID fields which are only useful for NVGRE encapsulation.
      Values are encoded as 1-byte quantity.

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3. NVO3 Flow Specification Traffic Actions

   The current traffic filtering actions are used for NVO3 encapsulation
   traffic. For Traffic Marking, only the DSCP in the outer header can
   be modified.

4. Security Considerations

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

5. IANA Considerations

   IANA is requested to assign three new values in the "Flow Spec
   Component Types" registry as follows:

      Type    Name            Reference
      ----   --------------   ---------
      TBD1   Delimiter type   [this document]
      TBD2   VN ID            [this document]
      TBD3   Flow ID          [this document]

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Normative References

   [RFC2119] - Bradner, S., "Key words for use in RFCs to Indicate
         Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119,
         March 1997, <>.

   [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,

   [RFC8174] - [RFC8174] - Leiba, B., "Ambiguity of Uppercase vs
         Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI
         10.17487/RFC8174, May 2017, <https://www.rfc->.

   [GENEVE] - J. Gross, T. Sridhar, etc, "Geneve: Generic Network
         Virtualization Encapsulation", draft-ietf-nvo3-geneve, work in

   [GUE] - T. Herbert, L. Yong, O. Zia, "Generic UDP Encapsulation",
         draft-ietf-nvo3-gue, work in progress.

Informative References

   [RFC7348] - Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
         L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
         eXtensible Local Area Network (VXLAN): A Framework for
         Overlaying Virtualized Layer 2 Networks over Layer 3 Networks",
         RFC 7348, DOI 10.17487/RFC7348, August 2014, <https://www.rfc->.

   [RFC7367] - Garg, P., Ed., and Y. Wang, Ed., "NVGRE: Network
         Virtualization Using Generic Routing Encapsulation", RFC 7637,
         DOI 10.17487/RFC7637, September 2015, <https://www.rfc->.

   [IPv6-FlowSpec] - R. Raszuk, etc, "Dissemination of Flow
         Specification Rules for IPv6", draft-ietf-idr-flow-spec-v6,
         work in progress.

   [Layer2-FlowSpec] - W. Hao, etc, "Dissemination of Flow Specification
         Rules for L2 VPN", draft-ietf-idr-flowspec-l2vpn, work in

   [GPE] - P. Quinn, etc, "Generic Protocol Extension for VXLAN", draft-
         ietf-nvo3-vxlan-gpe, work in progress.

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   The authors wish to acknowledge the important contributions of Jeff
   Haas, Susan Hares, Qiandeng Liang, Nan Wu, Yizhou Li, and Lucy Yong.

Authors' Addresses

      Donald Eastlake
      Huawei Technologies
      1424 Pro Shop Court
      Davenport, FL 33896 USA

      Tel: +1-508-333-2270

      Weiguo Hao
      Huawei Technologies
      101 Software Avenue,
      Nanjing 210012 China


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


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


      Rong Gu
      China Mobile


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