IDR Working Group                                            J. Tantsura
Internet-Draft                                          Juniper Networks
Intended status: Standards Track                                 Z. Wang
Expires: December 3, 2021                                          Q. Wu
                                                                  Huawei
                                                           K. Talaulikar
                                                           Cisco Systems
                                                            June 1, 2021


Distribution of Traffic Engineering Extended Administrative Groups using
                                 BGP-LS
                   draft-ietf-idr-eag-distribution-18

Abstract

   Administrative groups are link attributes used for traffic
   engineering.  This document defines an extension to BGP-LS for
   advertisement of extended administrative groups (EAGs).

Status of This Memo

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

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   This Internet-Draft will expire on December 3, 2021.

Copyright Notice

   Copyright (c) 2021 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
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   to this document.  Code Components extracted from this document must



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   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
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  Advertising Extended Administrative Group in BGP-LS . . . . .   3
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   4.  Manageability Considerations  . . . . . . . . . . . . . . . .   4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   5
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Administrative groups (commonly referred to as "colors" or "link
   colors") are link attributes that are advertised by link state
   protocols like IS-IS [RFC1195], OSPFv2 [RFC2328] and OSPFv3
   [RFC5340].  The BGP-LS advertisement of the originally defined (non-
   extended) administrative groups is encoded using the Administrative
   Group (color) TLV 1088 as defined in [RFC7752].

   These administrative groups are defined as a fixed-length 32-bit
   bitmask.  As networks grew and more use-cases were introduced, the
   32-bit length was found to be constraining and hence extended
   administrative groups (EAG) were introduced in [RFC7308].

   The EAG TLV (Section 2) is not a replacement for the Administrative
   Group (color) TLV; as explained in [RFC7308] both values can coexist.
   It is out of scope for this document to specify the behavior of the
   BGP-LS consumer [RFC7752].

   This document specifies an extension to BGP-LS for advertisement of
   the extended administrative groups.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "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.




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2.  Advertising Extended Administrative Group in BGP-LS

   This document defines an extension that enables BGP-LS speakers to
   signal the EAG of links in a network to a BGP-LS consumer of network
   topology such as a centralized controller.  The centralized
   controller can leverage this information in traffic engineering
   computations and other use-cases.  When a BGP-LS speaker is
   originating the topology learnt via link-state routing protocols like
   OSPF or IS-IS, the EAG information of the links is sourced from the
   underlying extensions as defined in [RFC7308].

   The EAG of a link is encoded in a new Link Attribute TLV [RFC7752]
   using the following format:

      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            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Extended Administrative Group (variable)                 //
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 1: Extended Administrative Group TLV Format

   Where:

   o  Type: 1173

   o  Length: variable length which represents the total length of the
      value field in octets.  The length value MUST be a multiple of 4.
      If the length is not a multiple of 4, the TLV MUST be considered
      malformed.

   o  Value: one or more sets of 32-bit bitmasks that indicate the
      administrative groups (colors) that are enabled on the link when
      those specific bits are set.

3.  IANA Considerations

   This document requests assigning a code-point from the registry "BGP-
   LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute
   TLVs" based on table below.  Early allocation for these code-points
   have been done by IANA.








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    +------------+-------------------------------+-------------------+
    | Code Point |   Description                 | IS-IS TLV/Sub-TLV |
    +------------+-------------------------------+-------------------+
    |   1173     | Extended Administrative Group |      22/14        |
    +------------+-------------------------------+-------------------+


4.  Manageability Considerations

   The new protocol extensions introduced in this document augment the
   existing IGP topology information that is distributed via [RFC7752].
   Procedures and protocol extensions defined in this document do not
   affect the BGP protocol operations and management other than as
   discussed in the Manageability Considerations section of [RFC7752].
   Specifically, the malformed attribute tests for syntactic checks in
   the Fault Management section of [RFC7752] now encompass the new BGP-
   LS Attribute TLV defined in this document.  The semantic or content
   checking for the TLV specified in this document and its association
   with the BGP-LS NLRI types or its BGP-LS Attribute is left to the
   consumer of the BGP-LS information (e.g. an application or a
   controller) and not the BGP protocol.

   A consumer of the BGP-LS information retrieves this information over
   a BGP-LS session (refer Section 1 and 2 of [RFC7752]).

5.  Security Considerations

   The procedures and protocol extensions defined in this document do
   not affect the BGP security model.  See the "Security Considerations"
   section of [RFC4271] for a discussion of BGP security.  This document
   only introduces a new Attribute TLV and any syntactic error in it
   would result in the BGP-LS Attribute being discarded [RFC7752].
   Also, refer to [RFC4272] and [RFC6952] for analyses of security
   issues for BGP.  Security considerations for acquiring and
   distributing BGP-LS information are discussed in [RFC7752].  The TLV
   introduced in this document is used to propagate the EAG extensions
   defined in [RFC7308].  It is assumed that the IGP instances
   originating this TLV will support all the required security (as
   described in [RFC7308]) and the OSPF and IS-IS RFCs below, in order
   to prevent any security issues when propagating the Sub-TLVs into
   BGP-LS.

   Security concerns for OSPF are addressed in [RFC7474], [RFC4552] and
   [RFC7166].  Further security analysis for OSPF protocol is done in
   [RFC6863].

   Security considerations for IS-IS are specified by [RFC5304].




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   The advertisement of the link attribute information defined in this
   document presents no significant additional risk beyond that
   associated with the existing link attribute information already
   supported in [RFC7752].

6.  Acknowledgments

   The authors would like to thank Eric Osborne, Les Ginsberg, Tim
   Chown, Ben Niven-Jenkins and Alvaro Retana for their reviews and
   valuable comments.

7.  References

7.1.  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,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC7308]  Osborne, E., "Extended Administrative Groups in MPLS
              Traffic Engineering (MPLS-TE)", RFC 7308,
              DOI 10.17487/RFC7308, July 2014,
              <https://www.rfc-editor.org/info/rfc7308>.

   [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>.

   [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-editor.org/info/rfc8174>.

7.2.  Informative References

   [RFC1195]  Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
              dual environments", RFC 1195, DOI 10.17487/RFC1195,
              December 1990, <https://www.rfc-editor.org/info/rfc1195>.

   [RFC2328]  Moy, J., "OSPF Version 2", STD 54, RFC 2328,
              DOI 10.17487/RFC2328, April 1998,
              <https://www.rfc-editor.org/info/rfc2328>.







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   [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,
              <https://www.rfc-editor.org/info/rfc4271>.

   [RFC4272]  Murphy, S., "BGP Security Vulnerabilities Analysis",
              RFC 4272, DOI 10.17487/RFC4272, January 2006,
              <https://www.rfc-editor.org/info/rfc4272>.

   [RFC4552]  Gupta, M. and N. Melam, "Authentication/Confidentiality
              for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,
              <https://www.rfc-editor.org/info/rfc4552>.

   [RFC5304]  Li, T. and R. Atkinson, "IS-IS Cryptographic
              Authentication", RFC 5304, DOI 10.17487/RFC5304, October
              2008, <https://www.rfc-editor.org/info/rfc5304>.

   [RFC5340]  Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
              for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
              <https://www.rfc-editor.org/info/rfc5340>.

   [RFC6863]  Hartman, S. and D. Zhang, "Analysis of OSPF Security
              According to the Keying and Authentication for Routing
              Protocols (KARP) Design Guide", RFC 6863,
              DOI 10.17487/RFC6863, March 2013,
              <https://www.rfc-editor.org/info/rfc6863>.

   [RFC6952]  Jethanandani, M., Patel, K., and L. Zheng, "Analysis of
              BGP, LDP, PCEP, and MSDP Issues According to the Keying
              and Authentication for Routing Protocols (KARP) Design
              Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013,
              <https://www.rfc-editor.org/info/rfc6952>.

   [RFC7166]  Bhatia, M., Manral, V., and A. Lindem, "Supporting
              Authentication Trailer for OSPFv3", RFC 7166,
              DOI 10.17487/RFC7166, March 2014,
              <https://www.rfc-editor.org/info/rfc7166>.

   [RFC7474]  Bhatia, M., Hartman, S., Zhang, D., and A. Lindem, Ed.,
              "Security Extension for OSPFv2 When Using Manual Key
              Management", RFC 7474, DOI 10.17487/RFC7474, April 2015,
              <https://www.rfc-editor.org/info/rfc7474>.

Authors' Addresses







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   Jeff Tantsura
   Juniper Networks

   Email: jefftant.ietf@gmail.com


   Zitao Wang
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: wangzitao@huawei.com


   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: bill.wu@huawei.com


   Ketan Talaulikar
   Cisco Systems

   Email: ketant@cisco.com























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