IDR Working Group                                                  Z. Wu
Internet-Draft                                                   H. Wang
Intended status: Standards Track                                 L. Wang
Expires: 8 September 2022                                         Z. Tan
                                                     Huawei Technologies
                                                            7 March 2022


          BGP Flowspec Redirect Load Balancing Group Community
                draft-wu-idr-flowspec-redirect-group-00

Abstract

   This document defines an extension to "BGP Community Container
   Attribute" [I-D.ietf-idr-wide-bgp-communities] , which allows
   flowspec redirection to multiple paths.  This extended community
   serves to redirect traffic to a load balancing group and supports
   both equal-cost multi-path(ECMP) and unequal-cost multi-path(UCMP)
   scenarios.

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 8 September 2022.

Copyright Notice

   Copyright (c) 2022 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 (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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Redirect Load Balancing Group Community . . . . . . . . . . .   3
     2.1.  Community Value . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Param TLV . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.3.  Sub-TLVs(Atoms) . . . . . . . . . . . . . . . . . . . . .   5
       2.3.1.  Atom Type 1: IPv4 Prefix Only . . . . . . . . . . . .   6
       2.3.2.  Atom Type 2: IPv4 Prefix with Weight  . . . . . . . .   6
       2.3.3.  Atom Type 3: IPv4 Prefix with Color . . . . . . . . .   7
       2.3.4.  Atom Type 4: IPv4 Prefix with Color and Weight  . . .   8
       2.3.5.  Atom Type 5: IPv6 Prefix Only . . . . . . . . . . . .   8
       2.3.6.  Atom Type 6: IPv6 Prefix with Weight  . . . . . . . .   9
       2.3.7.  Atom Type 7: IPv6 Prefix with Color . . . . . . . . .  10
       2.3.8.  Atom Type 8: IPv6 Prefix with Color and Weight  . . .  10
   3.  Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . .  11
     3.1.  ECMP  . . . . . . . . . . . . . . . . . . . . . . . . . .  11
     3.2.  UCMP  . . . . . . . . . . . . . . . . . . . . . . . . . .  11
   4.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .  12
     4.1.  Redirect Group Wide Community Parameter TLV . . . . . . .  12
     4.2.  Redirect Group Wide Community Parameter Sub-TLVs  . . . .  12
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
     5.1.  BGP Wide Communities Community Type : Redirect Group  . .  12
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     7.2.  References  . . . . . . . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   "Redirect to IP Extended Community", defined in
   [I-D.ietf-idr-flowspec-redirect-ip], allows traffic to be redirected
   to a specific IPv4 or IPv6 address, and
   [I-D.jiang-idr-ts-flowspec-srv6-policy] defines the redirection
   action to a SRv6 tunnel by additionally carrying the "Color Extended
   Community" [RFC8955].




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   However, scenarios involving redirection load balancing are not
   described in both documents.  Although in some implementations,
   Equal-cost multi-path(ECMP) of "Redirect to IP" action can be
   achieved by encoding multiple redirect Extended Communities, the
   current set of mechanisms can hardly support neither ECMP of SRv6
   tunnels nor unequal-cost multi-path(UCMP) of either types.

   This document defines an extension to "BGP Community Container
   Attribute" [I-D.ietf-idr-wide-bgp-communities], the "Redirect Load
   Balancing Group" community.  It is a new type of wide community
   container attribute with encoding format of multiple redirection path
   TLVs.  Each of these TLVs represents a different redirection action.
   It allows traffic redirection to a load balancing group and supports
   both ECMP and UCMP scenarios.

1.1.  Terminology

   This document introduces the following terms:

   ECMP:  Equal-Cost Multi-Path

   UCMP:  Unequal-Cost Multi-Path

2.  Redirect Load Balancing Group Community

   This document defines a new type of "BGP Community Container
   Attribute", the "Redirect Load Balancing Group" community type.  The
   format complies with "BGP Community Container Attribute"
   [I-D.ietf-idr-wide-bgp-communities] and is shown 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              |    Flags  |C|T|   Reserved    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Community Value: Redirect Load Balancing Group        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Source AS Number                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Context AS Number                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Param TLV   |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                        sub-TLVs                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 1: Redirect Load Balancing Group Community Format

   The Type, Flags, Reserved and Length fields comply with the "BGP
   Community Container Attribute Common Header" definition.

   The container type MUST be 1, which represents BGP Wide Community.

   The Length field represents the total length of the container's
   contents in octets.

2.1.  Community Value

   The Community Value, Source AS Number and Context AS Number fields
   comply with the corresponding definition in "BGP Community Container
   Attribute".

   Community Value: 4 octets value that represents the "Redirect Load
   Balancing Group" community type.  The value is TBD and requires IANA
   registration; See Section 5.1.

2.2.  Param TLV

   The BGP Wide Community Parameter TLV (Sub-Type 3) contains a list of
   atoms, comply with "BGP Wide Community Parameter(s) TLV" section of
   "BGP Community Container Attribute".






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   The Parameter TLV MUST present and SHOULD appear only once in a
   "Redirect Load Balancing Group" community container, no or multiple
   present SHOULD be considered malformed.

   Sub-Type: Type 3 (BGP Wide Community Parameter TLV)

   Length: Length of all the sub-TLVs in octets.

2.3.  Sub-TLVs(Atoms)

   The list of atoms that Param Tlv contains.  Each atom represents a
   different redirection path.

   The general format of the sub-TLVs comply with atoms' format defined
   in "BGP Community Container Attribute", as 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      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Value                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 2: Param Sub-TlV Format

   The Type field is an octet from 1~254 (0 and 255 are reserved).
   Supported type of the sub-TLVs includes:

   Type 1:  IPv4 Prefix Only

   Type 2:  IPv4 Prefix with Weight

   Type 3:  IPv4 Prefix with Color

   Type 4:  IPv4 Prefix with Color and Weight

   Type 5:  IPv6 Prefix Only

   Type 6:  IPv6 Prefix with Weight

   Type 7:  IPv6 Prefix with Color

   Type 8:  IPv6 Prefix with Color and Weight





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   These sub-TLV types SHOULD be used exclusively within "Redirect Load
   Balancing Group" community containers.

   The Length represents the length of the "Value" field in octets, and
   it is fixed for each specific sub-TLV.

   If the length and type of a sub-TLV do not match, the "Redirect Load
   Balancing Group" community container SHOULD be considered malformed.

   If a sub-TLV is a total dupilication of a previous one, the latter
   sub-TLV MUST be ignored.

   In principle, sub-TLVs of different types may be combined in any
   mode.  The supported combinations depend on the specific
   implementation.

2.3.1.  Atom Type 1: IPv4 Prefix Only

   Indicating the redirection path is unweighted and to a IPv4 address.
   The format is shown 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: 1    |   Length: 6                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            IPv4(4)                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 3: Atom Type 1: IPv4 Prefix Only

   Length: MUST be 6.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv4: 4-octet IPv4 address, redirection destination

2.3.2.  Atom Type 2: IPv4 Prefix with Weight

   Indicating the redirection path is weighted and to a IPv4 address.
   The format is shown 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: 2    |   Length: 7                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            IPv4(4)                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Weight(1)  |
   +-+-+-+-+-+-+-+-+

               Figure 4: Atom Type 2: IPv4 Prefix with Weight

   Length: MUST be 7.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv4: 4-octet IPv4 address, redirection destination

   Weight: 1 octet, values from 1~255, load balancing weight

2.3.3.  Atom Type 3: IPv4 Prefix with Color

   Indicating the redirection path is unweighted and to a SR-TE tunnel.
   The format is shown 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: 3    |   Length: 10                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            IPv4(4)                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Color(4)                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 5: Atom Type 3: IPv4 Prefix with Color

   Length: MUST be 10.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv4: 4-octet IPv4 address, SR-TE tunnel Endpoint for redirection



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   Color: 4 octets, SR-TE tunnel Color for redirection

2.3.4.  Atom Type 4: IPv4 Prefix with Color and Weight

   Indicating the redirection path is weighted and to a SR-TE tunnel.
   The format is shown 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: 4    |   Length: 11                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            IPv4(4)                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Color(4)                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Weight(1)  |
   +-+-+-+-+-+-+-+-+

          Figure 6: Atom Type 4: IPv4 Prefix with Color and Weight

   Length: MUST be 11.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv4: 4-octet IPv4 address, SR-TE tunnel Endpoint for redirection

   Color: 4 octets, SR-TE tunnel Color for redirection

   Weight: 1 octet, values from 1~255, load balancing weight

2.3.5.  Atom Type 5: IPv6 Prefix Only

   Indicating the redirection path is unweighted and to a IPv6 address.
   The format is shown 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: 5    |   Length: 18                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           IPv6(16)                            |
   ~                                                               ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 7: Atom Type 5: IPv6 Prefix Only

   Length: MUST be 18.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv6: 16-octet IPv6 address, redirection destination

2.3.6.  Atom Type 6: IPv6 Prefix with Weight

   Indicating the redirection path is weighted and to a IPv6 address.
   The format is shown 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: 6    |   Length: 19                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           IPv6(16)                            |
   ~                                                               ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Weight(1)  |
   +-+-+-+-+-+-+-+-+

               Figure 8: Atom Type 6: IPv6 Prefix with Weight

   Length: MUST be 19.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv6: 16-octet IPv6 address, redirection destination

   Weight: 1 octet, values from 1~255, load balancing weight



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2.3.7.  Atom Type 7: IPv6 Prefix with Color

   Indicating the redirection path is unweighted and to a SRv6 tunnel.
   The format is shown 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: 7    |   Length: 22                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           IPv6(16)                            |
   ~                                                               ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Color(4)                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 9: Atom Type 7: IPv6 Prefix with Color

   Length: MUST be 22.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv6: 16-octet IPv6 address, SRv6 tunnel Endpoint for redirection

   Color: 4 octets, SRv6 tunnel Color for redirection

2.3.8.  Atom Type 8: IPv6 Prefix with Color and Weight

   Indicating the redirection path is weighted and to a SRv6 tunnel.
   The format is shown 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: 8    |   Length: 23                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Flag(2)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           IPv6(16)                            |
   ~                                                               ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Color(4)                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Weight(1)  |
   +-+-+-+-+-+-+-+-+



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         Figure 10: Atom Type 8: IPv6 Prefix with Color and Weight

   Length: MUST be 23.

   Flags: 2 octets, reserved for future use, MUST be set to 0 upon the
   sender and MUST be ignored upon the reciever.

   IPv6: 16-octet IPv6 address, SRv6 tunnel Endpoint for redirection

   Color: 4 octets, SRv6 tunnel Color for redirection

   Weight: 1 octet, values from 1~255, load balancing weight

3.  Scenarios

   This section describes a few use-case scenarios when deploying
   "Redirect Load Balancing Group" community type.

   Weighted atom types:  Atoms contain a Weight field, such as Type 2,
      4, 6, 8

   Unweighted atom types:  Atoms do not contain a Weight field, such as
      Type 1, 3, 5, 7

3.1.  ECMP

   A system that originates a flowspec route with a "Redirect Load
   Balancing Group" community, among which its parameter TLV contains
   more than 1 atoms.  If not all atoms are of a weighted type, these
   atoms will form a ECMP group.

   Implementations MUST be prepared to accept a Parameter TLV with both
   weighted and unweighted atoms.  In this case, the Weight field of the
   weighted atom SHOULD be ignored.

3.2.  UCMP

   A system that originates a flowspec route with a "Redirect Load
   Balancing Group" community, among which its parameter TLV contains
   more than 1 atoms.  If all atoms are of a weighted type, these atoms
   will form a UCMP group.

   In this case, the Weight field value of these atoms SHOULD NOT be
   ignored, and the values are used as the ratio of the UCMP group.







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4.  Error Handling

   Comply with Error Handling Procedure in "BGP Community Container
   Attribute" [I-D.ietf-idr-wide-bgp-communities].

   In addition:

4.1.  Redirect Group Wide Community Parameter TLV

   A "Redirect Load Balancing Group" community container with no or
   multiple parameter TLVs SHOULD be considered malformed, and a "treat
   as withdraw" behavior is expected.

4.2.  Redirect Group Wide Community Parameter Sub-TLVs

   If the length and type of a sub-TLV do not match, the "Redirect Load
   Balancing Group" community container SHOULD be considered malformed,
   and a "treat as withdraw" behavior is expected.

5.  IANA Considerations


5.1.  BGP Wide Communities Community Type : Redirect Group

   This document requests a new community value under "Registered Type 1
   BGP Wide Community Community Types" registery.  This registery is
   defined and requested in "BGP Community Container Attribute"
   [I-D.ietf-idr-wide-bgp-communities].

   Requested value:

                Name                             Type Value
                ----                             ----------
                Redirect Load Balancing Group       TBD

6.  Security Considerations

   A system that originates a flowspec route with a "Redirect Load
   Balancing Group" BGP wide community can cause many receivers of that
   route to redirect traffic to a single next-hop, overwhelming that
   next-hop and resulting in inadvertent or deliberate denial-of-
   service.  This is also a concern about the "redirect to IP" extended
   community, therefore this document introduces no additional security
   considerations than those already covered in [RFC8955].

7.  References

7.1.  Normative References



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   [I-D.ietf-idr-flowspec-redirect-ip]
              Uttaro, J., Haas, J., Texier, M., Karch, A., Ray, S.,
              Simpson, A., and W. Henderickx, "BGP Flow-Spec Redirect to
              IP Action", Work in Progress, Internet-Draft, draft-ietf-
              idr-flowspec-redirect-ip-02, 5 February 2015,
              <https://www.ietf.org/archive/id/draft-ietf-idr-flowspec-
              redirect-ip-02.txt>.

   [I-D.ietf-idr-wide-bgp-communities]
              Raszuk, R., Haas, J., Lange, A., Decraene, B., Amante, S.,
              and P. Jakma, "BGP Community Container Attribute", Work in
              Progress, Internet-Draft, draft-ietf-idr-wide-bgp-
              communities-06, 10 January 2022,
              <https://www.ietf.org/archive/id/draft-ietf-idr-wide-bgp-
              communities-06.txt>.

   [I-D.jiang-idr-ts-flowspec-srv6-policy]
              Jiang, W., Liu, Y., and S. Chen, "Traffic Steering using
              BGP Flowspec with SRv6 Policy", Work in Progress,
              Internet-Draft, draft-jiang-idr-ts-flowspec-srv6-policy-
              04, 11 July 2021, <https://www.ietf.org/archive/id/draft-
              jiang-idr-ts-flowspec-srv6-policy-04.txt>.

   [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>.

7.2.  References

   [RFC8955]  Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
              Bacher, "Dissemination of Flow Specification Rules",
              RFC 8955, DOI 10.17487/RFC8955, December 2020,
              <https://www.rfc-editor.org/info/rfc8955>.

   [RFC8956]  Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed.,
              "Dissemination of Flow Specification Rules for IPv6",
              RFC 8956, DOI 10.17487/RFC8956, December 2020,
              <https://www.rfc-editor.org/info/rfc8956>.

Authors' Addresses

   Zhiwen Wu
   Huawei Technologies
   No. 156 Beiqing Road
   Beijing
   100095
   P.R. China



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   Email: wuzhiwen1@huawei.com


   Haibo Wang
   Huawei Technologies
   No. 156 Beiqing Road
   Beijing
   100095
   P.R. China
   Email: rainsword.wang@huawei.com


   Lili Wang
   Huawei Technologies
   No. 156 Beiqing Road
   Beijing
   100095
   P.R. China
   Email: lily.wong@huawei.com


   Zhen Tan
   Huawei Technologies
   No. 156 Beiqing Road
   Beijing
   100095
   P.R. China
   Email: tanzhen6@huawei.com























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