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Versions: 00 01 02 03 04

IDR Working Group                                                H. Chen
Internet-Draft                                                 Futurewei
Intended status: Standards Track                                   Z. Li
Expires: May 2, 2020                                              Huawei
                                                                   Z. Li
                                                            China Mobile
                                                                  Y. Fan
                                                            Casa Systems
                                                                  M. Toy
                                                                 Verizon
                                                                  L. Liu
                                                                 Fujitsu
                                                        October 30, 2019


                   BGP Extensions for IDs Allocation
               draft-wu-idr-bgp-segment-allocation-ext-04

Abstract

   This document describes extensions to the BGP for IDs allocation.
   The IDs are SIDs for segment routing (SR), including SR for IPv6
   (SRv6).  They are distributed to their domains if needed.

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 May 2, 2020.





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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.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Protocol Extensions . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Node SID NLRI TLV . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Link SID NLRI TLV . . . . . . . . . . . . . . . . . . . .   6
     3.3.  Prefix SID NLRI TLV . . . . . . . . . . . . . . . . . . .  10
     3.4.  Capability Negotiation  . . . . . . . . . . . . . . . . .  11
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   In a network with a central controller, the controller has the link
   state information of the network, including the resource such as
   traffic enginerring and SIDs information.  It is valuable for the
   controller to allocate and manage the resources including SIDs of the
   network in a centralized way, especially for the SIDs representing
   network resources [I-D.ietf-teas-enhanced-vpn].

   When BGP as a controller allocates an ID, it is natural and
   beneficial to extend BGP to send it to its corresponding network
   elements.

   PCE may be extended to send IDs to their corresponding network
   elements after the IDs are allocated by a controller.  However, when
   BGP is already deployed in a network, using PCE for IDs will need to



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   deploy an extra protocol PCE in the network.  This will increase the
   CapEx and OpEx.

   Yang may be extended to send IDs to their corresponding network
   elements after the IDs are allocated by a controller.  However, Yang
   progress may be slow.  Some people may not like this.

   There may not be these issues when BGP is used to send IDs.  In
   addition, BGP may be used to distribute IDs into their domains easily
   when needed.  It is also fit for the dynamic and static allocation of
   IDs.

   This document proposes extensions to the BGP for sending Segment
   Identifiers (SIDs) for segment routing (SR) including SRv6 to their
   corresponding network elements after SIDs are allocated by the
   controller.  If needed, they will be distributed into their network
   domains.

2.  Terminology

   The following terminology is used in this document.

   SR:  Segment Routing.

   SRv6:  SR for IPv6

   SID:  Segment Identifier.

   IID:  Indirection Identifier.

   SR-Path:  Segment Routing Path.

   SR-Tunnel:  Segment Routing Tunnel.

   RR:  Route Reflector.

   MPP:  MPLS Path Programming.

   NAI:  Node or Adjacency Identifier.

   TED:  Traffic Engineering Database.

3.  Protocol Extensions

   A new AFI and SAFI are defined: the Identifier AFI and the SID SAFI
   whose codepoints are to be assigned by IANA.  A few new NLRI TLVs are
   defined for the new AFI/SAFI, which are Node, Link and Prefix SID
   NLRI TLVs.  When a SID for a node, link or prefix is allocated by the



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   controller, it may be sent to a network element in a UPDATE message
   containing a MP_REACH NLRI with the new AFI/SAFI and the SID NLRI
   TLV.  When the SID is withdrawn by the controller, a UPDATE message
   containing a MP_UNREACH NLRI with the new AFI/SAFI and the SID NLRI
   TLV may be sent to the network element.

3.1.  Node SID NLRI TLV

   The Node SID NLRI TLV is used to represent the IDs such as SID
   associated with a node.  Its format is illustrated in the
   Figure below, which is similar to the corresponding one defined in
   [RFC7752].

      0                   1                   2                   3
      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 (TBDa for Node SID)   |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Protocol ID   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Identifier                          |
     |                           (8 octets)                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Peer IP (4/16 bytes for IPv4/IPv6 Address)                   ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Local Node Descriptors TLV                 ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                            Sub-TLVs                           ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where:

     Type (TBDa):  It is to be assigned by IANA.

     Length:  It is the length of the value field in bytes.

     Peer IP:  4/16 octet value indicates an IPv4/IPv6 peer.  When
      receiving a UPDATE message, a BGP speaker processes it only if the
      peer IP is the IP address of the BGP speaker or 0.

     Protocol-ID, Identifier, and Local Node Descriptor:  defined in
      [RFC7752], can be reused.

   Sub-TLVs may be some of the followings:

     SR-Capabilities TLV (1034):  It contains the Segment Routing Global
      Base (SRGB) range(s) allocated for the node.




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     SR Local Block TLV (1036):  The SR Local Block (SRLB) TLV contains
      the range(s) of SIDs/labels allocated to the node for local SIDs.

     SRv6 SID Node TLV (TBD1):  A new TLV, called SRv6 Node SID TLV,
      contains an SRv6 SID and related information.

     SRv6 Locator TLV (TBD2):  A new TLV, called SRv6 Locator TLV,
      contains an SRv6 locator and related information.

   The format of SRv6 SID Node TLV is illustrated below.

      0                   1                   2                   3
      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)          |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Reserved    |     Flags    |     SRv6 Endpoint Function    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        SRv6 Identifier                        |
     |                          (128 bits)                           |
     |                                                               |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     ~                        Optional sub-TLVs                      ~
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                             SRv6 Node SID TLV

   Type:  TBD1 for SRv6 Node SID TLV is to be assigned by IANA.

   Length:  Variable.

   Flags:  1 octet.  No flags are defined now.

   SRv6 Endpoint Function:  2 octets.  The function associated with SRv6
      SID.

   SRv6 Identifier:  16 octets.  IPv6 address representing SRv6 SID.

   Reserved:  MUST be set to 0 while sending and ignored on receipt.

   SRv6 node SID inherits the topology and algorithm from its locator.

   The format of SRv6 locator TLV is illustrated below.





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      0                   1                   2                   3
      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 (TBD2)          |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |R|R|R|R|          MT-ID        |   Algorithm   |     Flags     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Metric                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Locator-Size | Locator (variable)...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     ~                        Optional sub-TLVs                      ~
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                             SRv6 Locator TLV

   Type:  TBD2 for SRv6 Locator TLV is to be assigned by IANA.

   Length:  Variable.

   MT-ID:  Multitopology Identifier as defined in [RFC5120].

   Algorithm:  1 octet.  Associated algorithm.

   Flags:  1 octet.  As described in
      [I-D.ietf-lsr-isis-srv6-extensions].

   Metric:  4 octets.  As described in [RFC5305].

   Locator-Size:  1 octet.  Number of bits in the Locator field (1 to
      128).

   Locator:  1 to 16 octets.  SRv6 Locator encoded in the minimum number
      of octets for the given Locator-Size.

   Reserved:  MUST be set to 0 while sending and ignored on receipt.

3.2.  Link SID NLRI TLV

   The Link SID NLRI TLV is used to represent the IDs such as SID
   associated with a link.  Its format is illustrated in the
   Figure below, which is similar to the corresponding one defined in
   [RFC7752].






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      0                   1                   2                   3
      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 (TBDb for Link SID)   |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Protocol ID   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Identifier (8 octets)                      ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Peer IP (4/16 bytes for IPv4/IPv6 Address)                   ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Local Node Descriptors TLV                 ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Remote Node Descriptors TLV                ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                        Link Descriptors TLV                   ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                            Sub-TLVs                           ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where:

     Type (TBDb):  It is to be assigned by IANA.

     Length:  It is the length of the value field in bytes.

     Peer IP:  4/16 octet value indicates an IPv4/IPv6 peer.

     Protocol-ID, Identifier, Local Node Descriptors,    Remote Node
   Descriptors and Link Descriptors:
      defined in [RFC7752], can be reused.

   The Sub-TLVs may be some of the followings:

     Adj-SID TLV (1099):  It contains the Segment Identifier (SID)
      allocated for the link/adjacency.

     LAN Adj-SID TLV (1100):  It contains the Segment Identifier (SID)
      allocated for the adjacency/link to a non-DR router on a
      broadcast, NBMA, or hybrid link.

     SRv6 Adj-SID TLV (TBD3):  A new TLV, called SRv6 Adj-SID TLV,
      contains an SRv6 Adj-SID and related information.

     SRv6 LAN Adj-SID TLV (TBD4):  A new TLV, called SRv6 LAN Adj-SID
      TLV, contains an SRv6 LAN Adj-SID and related information.

   The format of an SRv6 Adj-SID TLV is illustrated below.



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      0                   1                   2                   3
      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 (TBD3)          |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Weight    |   Algorithm   |B|S|P|             Flags       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |           Reserved            |     SRv6 Endpoint Function    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        SRv6 Identifier                        |
     |                          (128 bits)                           |
     |                                                               |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     ~                        Optional sub-TLVs                      ~
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                              SRv6 Adj-SID TLV

   Type:  TBD3 for SRv6 Adj-SID TLV is to be assigned by IANA.

   Length:  Variable.

   Weight:  1 octet.  The value represents the weight of the SID for the
      purpose of load balancing.

   Algorithm:  1 octet.  Associated algorithm.

   Flags:  2 octets.  Three flags are defined in
      [I-D.ietf-lsr-isis-srv6-extensions].

   SRv6 Endpoint Function:  2 octets.  The function associated with SRv6
      SID.

   SRv6 Identifier:  16 octets.  IPv6 address representing SRv6 SID.

   Reserved:  MUST be set to 0 while sending and ignored on receipt.

   The format of an SRv6 LAN Adj-SID TLV is illustrated below.










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      0                   1                   2                   3
      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 (TBD4)          |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Weight    |   Algorithm   |B|S|P|             Flags     |O|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |           Reserved            |     SRv6 Endpoint Function    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    neighbor Router ID (4 octets) / System ID (6 octets)       ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        SRv6 Identifier                        |
     |                          (128 bits)                           |
     |                                                               |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     ~                        Optional sub-TLVs                      ~
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                            SRv6 LAN Adj-SID TLV

   Type:  TBD4 for SRv6 LAN Adj-SID TLV is to be assigned by IANA.

   Length:  Variable.

   Weight:  1 octet.  The value represents the weight of the SID for the
      purpose of load balancing.

   Algorithm:  1 octet.  Associated algorithm.

   Flags:  2 octets.  Three flags B, S and P are defined in
      [I-D.ietf-lsr-isis-srv6-extensions].  Flag O set to 1 indicating
      OSPF neighbor Router ID of 4 octets, set to 0 indicating IS-IS
      neighbor System ID of 6 octets.

   SRv6 Endpoint Function:  2 octets.  The function associated with SRv6
      SID.

   SRv6 Identifier:  16 octets.  IPv6 address representing SRv6 SID.

   Reserved:  MUST be set to 0 while sending and ignored on receipt.








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3.3.  Prefix SID NLRI TLV

   The Prefix SID NLRI TLV is used to represent the IDs such as SID
   associated with a prefix.  Its format is illustrated in the
   Figure below, which is similar to the corresponding one defined in
   [RFC7752].

      0                   1                   2                   3
      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 (TBDc for Prefix SID)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Protocol ID   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                       Identifier (8 octets)                   ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Peer IP (4/16 bytes for IPv4/IPv6 Address)                   ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Local Node Descriptors TLV                 ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                        Prefix Descriptors TLV                 ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                            Sub-TLVs                           ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where:

     Type (TBDc):  It is to be assigned by IANA.

     Length:  It is the length of the value field in bytes.

     Peer IP:  4/16 octet value indicates an IPv4/IPv6 peer.

     Protocol-ID, Identifier, Local Node Descriptors and    Prefix
   Descriptors:
      defined in [RFC7752], can be reused.

   Sub-TLVs may be some of the followings:

     Prefix-SID TLV (1158):  It contains the Segment Identifier (SID)
      allocated for the prefix.

     Prefix Range TLV (1159):  It contains a range of prefixes and the
      Segment Identifier (SID)s allocated for the prefixes.







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3.4.  Capability Negotiation

   It is necessary to negotiate the capability to support BGP Extensions
   for sending and receiving Segment Identifiers (SIDs).  The BGP SID
   Capability is a new BGP capability [RFC5492].  The Capability Code
   for this capability is to be specified by the IANA.  The Capability
   Length field of this capability is variable.  The Capability Value
   field consists of one or more of the following tuples:

           +--------------------------------------------------+
           |  Address Family Identifier (2 octets)            |
           +--------------------------------------------------+
           |  Subsequent Address Family Identifier (1 octet)  |
           +--------------------------------------------------+
           |  Send/Receive (1 octet)                          |
           +--------------------------------------------------+

                          BGP SID Capability

   The meaning and use of the fields are as follows:

   Address Family Identifier (AFI): This field is the same as the one
   used in [RFC4760].

   Subsequent Address Family Identifier (SAFI): This field is the same
   as the one used in [RFC4760].

   Send/Receive: This field indicates whether the sender is (a) willing
   to receive SID from its peer (value 1), (b) would like to send SID to
   its peer (value 2), or (c) both (value 3) for the <AFI, SAFI>.

4.  IANA Considerations

   This document requests assigning a new AFI in the registry "Address
   Family Numbers" as follows:

             +-------------+---------------------+-------------+
             | Code Point  | Description         | Reference   |
             +-------------+---------------------+-------------+
             |    TBDx     |  Identifier AFI     |This document|
             +-------------+---------------------+-------------+

   This document requests assigning a new SAFI in the registry
   "Subsequent Address Family Identifiers (SAFI) Parameters" as follows:







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             +-------------+----------------------+-------------+
             | Code Point  | Description          | Reference   |
             +-------------+----------------------+-------------+
             |    TBDy     |  SID SAFI            |This document|
             +-------------+----------------------+-------------+

   This document defines a new registry called "SID NLRI TLVs".  The
   allocation policy of this registry is "First Come First Served
   (FCFS)" according to [RFC8126].

   Following TLV code points are defined:

      +-------------+-----------------------------------+-------------+
      | Code Point  | Description                       | Reference   |
      +-------------+-----------------------------------+-------------+
      |  1 (TBDa)   | Node SID NLRI                     |This document|
      +-------------+-----------------------------------+-------------+
      |  2 (TBDb)   | Link SID NLRI                     |This document|
      +-------------+-----------------------------------+-------------+
      |  3 (TBDc)   | Prefix SID NLRI                   |This document|
      +-------------+-----------------------------------+-------------+

   This document requests assigning a code-point from the registry "BGP-
   LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute
   TLVs" as follows:

    +----------------+-----------------------------------+-------------+
    | TLV Code Point | Description                       | Reference   |
    +----------------+-----------------------------------+-------------+
    |     TBD1       | SRv6 Node SID                     |This document|
    +----------------+-----------------------------------+-------------+
    |     TBD2       | SRv6 Allocator                    |This document|
    +----------------+-----------------------------------+-------------+
    |     TBD3       | SRv6 Adj-SID                      |This document|
    +----------------+-----------------------------------+-------------+
    |     TBD4       | SRv6 LAN Adj-SID                  |This document|
    +----------------+-----------------------------------+-------------+

5.  Security Considerations

   Protocol extensions defined in this document do not affect the BGP
   security other than those as discussed in the Security Considerations
   section of [RFC7752].








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6.  Acknowledgements

   The authors would like to thank Eric Wu, Robert Raszuk, Zhengquiang
   Li, and Ketan Talaulikar for their valuable suggestions and comments
   on this draft.

7.  References

7.1.  Normative References

   [I-D.ietf-idr-flowspec-path-redirect]
              Velde, G., Patel, K., and Z. Li, "Flowspec Indirection-id
              Redirect", draft-ietf-idr-flowspec-path-redirect-10 (work
              in progress), October 2019.

   [I-D.ietf-isis-segment-routing-extensions]
              Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A.,
              Gredler, H., and B. Decraene, "IS-IS Extensions for
              Segment Routing", draft-ietf-isis-segment-routing-
              extensions-25 (work in progress), May 2019.

   [I-D.ietf-lsr-isis-srv6-extensions]
              Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and
              Z. Hu, "IS-IS Extension to Support Segment Routing over
              IPv6 Dataplane", draft-ietf-lsr-isis-srv6-extensions-03
              (work in progress), October 2019.

   [I-D.ietf-rtgwg-bgp-routing-large-dc]
              Lapukhov, P., Premji, A., and J. Mitchell, "Use of BGP for
              routing in large-scale data centers", draft-ietf-rtgwg-
              bgp-routing-large-dc-11 (work in progress), June 2016.

   [I-D.ietf-spring-segment-routing]
              Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B.,
              Litkowski, S., and R. Shakir, "Segment Routing
              Architecture", draft-ietf-spring-segment-routing-15 (work
              in progress), January 2018.

   [I-D.ietf-spring-segment-routing-ldp-interop]
              Bashandy, A., Filsfils, C., Previdi, S., Decraene, B., and
              S. Litkowski, "Segment Routing interworking with LDP",
              draft-ietf-spring-segment-routing-ldp-interop-15 (work in
              progress), September 2018.

   [I-D.li-ospf-ospfv3-srv6-extensions]
              Li, Z., Hu, Z., Cheng, D., Talaulikar, K., and P. Psenak,
              "OSPFv3 Extensions for SRv6", draft-li-ospf-
              ospfv3-srv6-extensions-05 (work in progress), August 2019.



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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>.

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

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120,
              DOI 10.17487/RFC5120, February 2008,
              <https://www.rfc-editor.org/info/rfc5120>.

   [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
              Engineering", RFC 5305, DOI 10.17487/RFC5305, October
              2008, <https://www.rfc-editor.org/info/rfc5305>.

   [RFC5492]  Scudder, J. and R. Chandra, "Capabilities Advertisement
              with BGP-4", RFC 5492, DOI 10.17487/RFC5492, February
              2009, <https://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,
              <https://www.rfc-editor.org/info/rfc5575>.

   [RFC7752]  Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
              S. Ray, "North-Bound Distribution of Link-State and
              Traffic Engineering (TE) Information Using BGP", RFC 7752,
              DOI 10.17487/RFC7752, March 2016,
              <https://www.rfc-editor.org/info/rfc7752>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

7.2.  Informative References

   [I-D.gredler-idr-bgp-ls-segment-routing-extension]
              Gredler, H., Ray, S., Previdi, S., Filsfils, C., Chen, M.,
              and J. Tantsura, "BGP Link-State extensions for Segment
              Routing", draft-gredler-idr-bgp-ls-segment-routing-
              extension-02 (work in progress), October 2014.




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   [I-D.ietf-idr-bgpls-segment-routing-epe]
              Previdi, S., Talaulikar, K., Filsfils, C., Patel, K., Ray,
              S., and J. Dong, "BGP-LS extensions for Segment Routing
              BGP Egress Peer Engineering", draft-ietf-idr-bgpls-
              segment-routing-epe-19 (work in progress), May 2019.

   [I-D.ietf-teas-enhanced-vpn]
              Dong, J., Bryant, S., Li, Z., Miyasaka, T., and Y. Lee, "A
              Framework for Enhanced Virtual Private Networks (VPN+)
              Service", draft-ietf-teas-enhanced-vpn-03 (work in
              progress), September 2019.

Authors' Addresses

   Huaimo Chen
   Futurewei
   Boston, MA
   USA

   Email: Huaimo.chen@futurewei.com


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

   Email: lizhenbin@huawei.com


   Zhenqiang Li
   China Mobile
   No. 29 Finance Street, Xicheng District
   Beijing  100029
   P.R. China

   Email: li_zhenqiang@hotmail.com


   Yanhe Fan
   Casa Systems
   USA

   Email: yfan@casa-systems.com






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   Mehmet Toy
   Verizon
   USA

   Email: mehmet.toy@verizon.com


   Lei Liu
   Fujitsu
   USA

   Email: liulei.kddi@gmail.com







































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