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Versions: (draft-snijders-idr-shutdown) 00 01 02 03 04 05 06 07

IDR                                                          J. Snijders
Internet-Draft                                                       NTT
Updates: 4486 (if approved)                                     J. Heitz
Intended status: Standards Track                                   Cisco
Expires: September 4, 2017                                    J. Scudder
                                                                 Juniper
                                                           March 3, 2017


               BGP Administrative Shutdown Communication
                       draft-ietf-idr-shutdown-07

Abstract

   This document enhances the BGP Cease NOTIFICATION message
   "Administrative Shutdown" and "Administrative Reset" subcodes for
   operators to transmit a short freeform message to describe why a BGP
   session was shutdown or reset.  This document updates RFC 4486.

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 September 4, 2017.

Copyright Notice

   Copyright (c) 2017 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
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   Without obtaining an adequate license from the person(s) controlling
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   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

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

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 or reset.






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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 Error Subcode
   "Administrative Shutdown" or "Administrative Reset" followed by a
   length field and an UTF-8 encoded string.  The contents of the string
   are at the operator's discretion.

   The Cease NOTIFICATION message with a Shutdown Communication is
   encoded 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Error code 6  |    Subcode    |    Length     |     ...       \
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+               /
   \                                                               \
   /                 ... Shutdown Communication ...                /
   \                                                               \
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Subcode:  the Error Subcode value MUST be one of the following
      values: 2 ("Administrative Shutdown") or 4 ("Administrative
      Reset").

   Length:  this 8-bit field represents the length of the Shutdown
      Communication field in octets.  The length value MUST range from 0
      to 128 inclusive.  When the length value is zero, no Shutdown
      Communication field follows.

   Shutdown Communication:  to support international characters, the
      Shutdown Communication field MUST be encoded using UTF-8.  A
      receiving BGP speaker MUST NOT interpret invalid UTF-8 sequences.
      Note that when the Shutdown Communication contains multibyte
      characters, the number of characters will be less than the length
      value.  This field is not NUL terminated.

   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:



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   "[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.

5.  IANA Considerations

   Per this document, IANA is requested to reference this document at
   subcode "Administrative Shutdown", and at subcode "Administrative
   Reset" in the "Cease NOTIFICATION message subcodes" registry under
   the "Border Gateway Protocol (BGP) Parameters" group in addition to
   [RFC4486].

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
   specification minimizes the effects of visual spoofing by limiting
   the length of the Shutdown Communication.

   Users of this mechanism should be aware that unless a transport that
   provides integrity (such as TCP-AO [RFC5925]) is used for the BGP
   session in question, a Shutdown Communication message could be
   forged.  Unless a transport that provides confidentiality (such as
   IPSec [RFC4303]) is used, a Shutdown Communication message could be
   snooped by an attacker.  These issues are common to any BGP message
   but may be of greater interest in the context of this proposal since
   the information carried in the message is generally expected to be
   used for human-to-human 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



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   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
   o  pmacct
   o  OpenBGPD
   o  GoBGP
   o  FreeRangeRouting (frr)
   o  tcpdump (packet analyser)
   o  Wireshark (packet analyser)

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>.

   [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

   [RFC4303]  Kent, S., "IP Encapsulating Security Payload (ESP)",
              RFC 4303, DOI 10.17487/RFC4303, December 2005,
              <http://www.rfc-editor.org/info/rfc4303>.



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

   [RFC5925]  Touch, J., Mankin, A., and R. Bonica, "The TCP
              Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
              June 2010, <http://www.rfc-editor.org/info/rfc5925>.

   [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, John
   Heasley, Peter van Dijk, Arjen Zonneveld, James Bensley, Susan Hares,
   Saku Ytti, and Lou Berger.

Authors' Addresses

   Job Snijders
   NTT Communications
   Theodorus Majofskistraat 100
   Amsterdam  1065 SZ
   The Netherlands

   Email: job@ntt.net


   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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