IDR                                                          J. Snijders
Internet-Draft                                                       NTT
Updates: 4486 (if approved)                                     J. Heitz
Intended status: Standards Track                                   Cisco
Expires: June 3, 2017                                         J. Scudder
                                                                 Juniper
                                                       November 30, 2016


       BGP Administrative Shutdown with Additional Communication
                       draft-ietf-idr-shutdown-01

Abstract

   This document enhances the BGP Cease NOTIFICATION message
   "Administrative Shutdown" subcode for operators to transmit a short
   freeform message to describe why a BGP session was shutdown.

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 [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 http://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 June 3, 2017.

Copyright Notice

   Copyright (c) 2016 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



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   (http://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.  Shutdown Communication  . . . . . . . . . . . . . . . . . . .   2
   3.  Operational Considerations  . . . . . . . . . . . . . . . . .   3
   4.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .   3
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION   4
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   It can be troublesome for an operator to correlate a BGP-4 [RFC4271]
   session teardown in the network with a notice that was transmitted
   via off-line methods such email or telephone calls.  This document
   specifies a mechanism to transmit a short freeform UTF-8 [RFC3629]
   message as part of a Cease NOTIFICATION message [RFC4486] to inform
   the peer why the BGP session is being shutdown.

2.  Shutdown Communication

   If a BGP speaker decides to terminate its session with a BGP
   neighbor, then the BGP speaker MAY send to the neighbor a
   NOTIFICATION message with the Error Code "Cease" and the Error
   Subcode "Administrative Shutdown" followed by a freeform UTF-8
   encoded string with a REQUIRED maximum length of 128 octets.  The
   contents of the string are at the operator's discretion.

   The Shutdown Communication Cease NOTIFICATION message is encoded as
   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Error code 6  |   subcode 2   |    Length     |     ...       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                   ... Shutdown Communication ...              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                              ...                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Length value can range from 0 to 128 and indicates how many
   octets of Shutdown Communication follow.

   To support international characters, the Shutdown Communication field
   MUST be encoded using UTF-8.

   The sending BGP speaker SHOULD avoid octet values below 32 (control
   characters), however these values are legal.  Following UNICODE TR36
   [UTR36], Sec 3.1, the sending BGP speaker MUST encode messages in the
   "shortest form" and MUST NOT interpret messages in the "non-shortest
   form".  A receiving BGP speaker MUST NOT interpret invalid UTF-8
   sequences.

   Mechanisms concerning the reporting of information contained in the
   Shutdown Communication are implementation specific but SHOULD include
   methods such as SYSLOG [RFC5424].

3.  Operational Considerations

   Operators are encouraged to use the Shutdown Communication to inform
   their peers of the reason for the shutdown of the BGP session and
   include out-of-band reference materials.  An example of a useful
   Shutdown Communication would be:

   "[TICKET-1-1438367390] software upgrade, back in 2 hours"

   "[TICKET-1-1438367390]" is a ticket reference with significance to
   both the sender and receiver, followed by a brief human readable
   message regarding the reason for the BGP session shutdown followed by
   an indication about the length of the maintenance.  The receiver can
   now use the string 'TICKET-1-1438367390' to search in their email
   archive to find more details.

4.  Error Handling

   Any erroneous or malformed Shutdown Communication received SHOULD be
   logged for the attention of the operator and then MAY be discarded.




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5.  IANA Considerations

   Per this document, IANA is requested to reference this document at
   subcode "Administrative Shutdown" in the "Cease NOTIFICATION message
   subcodes" registry under the "Border Gateway Protocol (BGP)
   Parameters" group.

6.  Security Considerations

   This document uses UTF-8 encoding for the Shutdown Communication.
   There are a number of security issues with UNICODE.  Implementers and
   operator are advised to review UNICODE TR36 [UTR36] to learn about
   these issues.  This document guards against the technical issues
   outlined in UTR36 by REQUIRING "shortest form" encoding.  However,
   the visual spoofing due to character confusion still persists.  This
   document tries to minimize the effects of visual spoofing by allowing
   UNICODE only where local script is expected and needed, and by
   limiting the length of the Shutdown Communication.

7.  Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   The description of implementations in this section is intended to
   assist the IETF in its decision processes in progressing drafts to
   RFCs.  Please note that the listing of any individual implementation
   here does not imply endorsement by the IETF.  Furthermore, no effort
   has been spent to verify the information presented here that was
   supplied by IETF contributors.  This is not intended as, and must not
   be construed to be, a catalog of available implementations or their
   features.  Readers are advised to note that other implementations may
   exist.

   As of today these vendors have produced an implementation of the
   Shutdown Communication:

   o  ExaBGP

8.  References

8.1.  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,
              <http://www.rfc-editor.org/info/rfc2119>.




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   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
              2003, <http://www.rfc-editor.org/info/rfc3629>.

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

   [RFC4486]  Chen, E. and V. Gillet, "Subcodes for BGP Cease
              Notification Message", RFC 4486, DOI 10.17487/RFC4486,
              April 2006, <http://www.rfc-editor.org/info/rfc4486>.

8.2.  Informative References

   [RFC5424]  Gerhards, R., "The Syslog Protocol", RFC 5424,
              DOI 10.17487/RFC5424, March 2009,
              <http://www.rfc-editor.org/info/rfc5424>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <http://www.rfc-editor.org/info/rfc7942>.

   [UTR36]    Davis, M. and M. Suignard, "Unicode Security
              Considerations", Unicode Technical Report #36, August
              2010, <http://unicode.org/reports/tr36/>.

Appendix A.  Acknowledgements

   The authors would like to gratefully acknowledge Tom Scholl, David
   Freedman, Jared Mauch, Jeff Haas, Peter Hessler, Bruno Decraene, and
   John Heasley.

Authors' Addresses

   Job Snijders
   NTT Communications
   Theodorus Majofskistraat 100
   Amsterdam  1065 SZ
   NL

   Email: job@ntt.net








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   Jakob Heitz
   Cisco
   170 West Tasman Drive
   San Jose, CA  95054
   USA

   Email: jheitz@cisco.com


   John Scudder
   Juniper Networks
   1194 N. Mathilda Ave
   Sunnyvale, CA  94089
   USA

   Email: jgs@juniper.net



































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