Networking Working Group
Internet Engineering Task Force (IETF)                       L. Ginsberg
Internet-Draft                                                  N. Akiya
Intended status: Standards Track
Request for Comments: 7883                                 Cisco Systems
Expires: September 3, 2015
Category: Standards Track                                       N. Akiya
ISSN: 2070-1721                                      Big Switch Networks
                                                                 M. Chen
                                                                  Huawei
                                                           March 2, 2015
                                                               July 2016

    Advertising S-BFD Seamless Bidirectional Forwarding Detection (S-BFD)
                        Discriminators in IS-IS
               draft-ietf-isis-sbfd-discriminator-02.txt

Abstract

   This document defines a means of advertising one or more S-BFD Seamless
   Bidirectional Forwarding Detection (S-BFD) Discriminators using the
   IS-IS Router Capability CAPABILITY TLV.

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 an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
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   Internet-Drafts are draft documents valid the IETF community.  It has
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   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of six months this document, any errata,
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   This Internet-Draft will expire on September 3, 2015.
   http://www.rfc-editor.org/info/rfc7883.

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Table of Contents

   1. Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2 ....................................................3
   2. Encoding Format  . . . . . . . . . . . . . . . . . . . . . .   2 .................................................3
   3. IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3 .............................................4
   4. Security Considerations . . . . . . . . . . . . . . . . . . .   3 .........................................4
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   6. Normative References  . . . . . . . . . . . . . . . . . . . .   4 ............................................4
   Acknowledgements ...................................................5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4 .................................................5

1.  Introduction

   [S-BFD]

   [RFC7880] defines a simplified mechanism to use for using Bidirectional
   Forwarding Detection (BFD)[RFC5880]. (BFD) [RFC5880].  This mechanism depends on
   network nodes knowing the BFD discriminators which Discriminators that each node in the
   network has reserved for this purpose.  Use  The use of the Intermediate
   System to Intermediate System (IS-IS)[IS-IS] (IS-IS) [IS-IS] protocol is one
   possible means of advertising these discriminators.

   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].

2.  Encoding Format

   The IS-IS Router CAPABILITY TLV as defined in [RFC4971] will be used
   to advertise S-BFD discriminators. Seamless BFD (S-BFD) Discriminators.  A new sub-TLV is
   defined as described below.  S-BFD Discriminators sub-TLVs are
   formatted as specified in [RFC5305].

                                                  No. of octets
                 +-----------------------------+
                 | Type (to be assigned by (20)                   |     1
                 | IANA - suggested value 20)  |
                 +-----------------------------+
                 | Length (multiple of 4)      |     1
                 +-----------------------------+
                 | Discriminator Value(s)      |     4/Discriminator
                 :                             :
                 +-----------------------------+

   Inclusion

   The inclusion of the an S-BFD Discriminators sub-TLV in a Router Capability
   CAPABILITY TLV is optional.  Multiple S-BFD Discriminators sub-TLVs
   MAY be advertised by an IS.  When multiple S-BFD discriminators are
   advertised how  How a given discriminator is mapped to a
   specific use case when multiple S-BFD Discriminators are advertised
   is out of scope for this document.

   S-BFD discriminator Discriminator advertisements MAY be flooded within an area or
   throughout the domain domain, using the procedures specified in [RFC4971].
   The appropriate flooding scope depends on the intended use of S-BFD.
   If S-BFD use usage will be exclusively within a Level-1 area area, then area
   scope is appropriate.  If S-BFD usage will span different L1 areas Level-1
   areas, then domain scope is appropriate.

3.  IANA Considerations

   This document requires the definition of

   IANA has added a new sub-TLV in the Sub-
   TLVs "Sub-TLVs for TLV 242 242" registry.
   The value written below registration is a suggested
   value subject to assignment by IANA. as follows:

      Value  Description
    ----  ---------------------
      -----  --------------------
      20     S-BFD Discriminators

4.  Security Considerations

   Security concerns for IS-IS are addressed in [IS-IS], [RFC5304], and
   [RFC5310].  Introduction of the  The new S-BFD Discriminators sub-TLV
   introduces no does not introduce
   any new security risks for IS-IS.

   Advertisement of

   Advertising the S-BFD discriminators does make Discriminators makes it possible for attackers
   to initiate S-BFD sessions using the advertised information.  The
   vulnerabilities this poses and how to mitigate them are discussed in the Security Considerations section of [S-BFD].

6.
   [RFC7880].

5.  Normative References

   [IS-IS]    International Organization for Standardization,
              "Intermediate system System to Intermediate system System intra-domain
              routeing information exchange protocol for use in
              conjunction with the protocol for providing the
              connectionless-mode Network Service network service (ISO 8473), ISO/IEC
              10589:2002, Second Edition.", Nov 8473)",
              ISO Standard 10589, 2002.

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

   [RFC4971]  Vasseur, JP., Ed., Shen, N., Ed., and R. Aggarwal, Ed.,
              "Intermediate System to Intermediate System (IS-IS)
              Extensions for Advertising Router Information", RFC 4971,
              DOI 10.17487/RFC4971, July 2007. 2007,
              <http://www.rfc-editor.org/info/rfc4971>.

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

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

   [RFC5310]  Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R.,
              and M. Fanto, "IS-IS Generic Cryptographic
              Authentication", RFC 5310, DOI 10.17487/RFC5310,
              February 2009. 2009, <http://www.rfc-editor.org/info/rfc5310>.

   [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010.

   [S-BFD] 2010,
              <http://www.rfc-editor.org/info/rfc5880>.

   [RFC7880]  Pignataro, C., Ward, D., Akiya, N., Bhatia, M., and S.
              Pallagatti, "Seamless Bidirectional Forwarding Detection (S-BFD),
              draft-ietf-bfd-seamless-base-04(work in progress)",
              January 2015.

5.
              (S-BFD)", RFC 7880, DOI 10.17487/RFC7880, July 2016,
              <http://www.rfc-editor.org/info/rfc7880>.

Acknowledgements

   The authors wish to thank Sam Aldrin, Manav Bhatia, and Carlos
   Pignataro for input essential to defining the needed functionality.

Authors' Addresses

   Les Ginsberg
   Cisco Systems
   510 McCarthy Blvd.
   Milpitas, CA  95035
   USA
   United States of America

   Email: ginsberg@cisco.com

   Nobo Akiya
   Cisco Systems
   Big Switch Networks

   Email: nobo@cisco.com nobo.akiya.dev@gmail.com

   Mach(Guoyi) Chen
   Huawei

   Email: mach.chen@huawei.com