GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


rfc:rfc8203

Internet Engineering Task Force (IETF) J. Snijders Request for Comments: 8203 NTT Updates: 4486 J. Heitz Category: Standards Track Cisco ISSN: 2070-1721 J. Scudder

                                                               Juniper
                                                             July 2017
             BGP Administrative Shutdown Communication

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.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc8203.

Copyright Notice

 Copyright (c) 2017 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
 (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.

Snijders, et al. Standards Track [Page 1] RFC 8203 BGP Shutdown July 2017

Table of Contents

 1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
 2.  Shutdown Communication  . . . . . . . . . . . . . . . . . . .   2
 3.  Operational Considerations  . . . . . . . . . . . . . . . . .   3
 4.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .   4
 5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
 6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
 7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
   7.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
   7.2.  Informative References  . . . . . . . . . . . . . . . . .   5
 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 offline methods such as email or telephone calls.  This document
 updates [RFC4486] by specifying a mechanism to transmit a short
 freeform UTF-8 [RFC3629] message as part of a Cease NOTIFICATION
 message [RFC4271] to inform the peer why the BGP session is being
 shutdown or reset.

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.

2. Shutdown Communication

 If a BGP speaker decides to terminate its session with a BGP
 neighbor, and it sends a NOTIFICATION message with the Error Code
 "Cease" and Error Subcode "Administrative Shutdown" or
 "Administrative Reset" [RFC4486], it MAY include an UTF-8 encoded
 string.  The contents of the string are at the operator's discretion.

Snijders, et al. Standards Track [Page 2] RFC 8203 BGP Shutdown July 2017

 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 ...                /
 \                                                               \
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                               Figure 1
 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:
 "[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

Snijders, et al. Standards Track [Page 3] RFC 8203 BGP Shutdown July 2017

 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

 If a Shutdown Communication with an invalid Length value, or an
 invalid UTF-8 sequence is received, a message indicating this event
 SHOULD be logged for the attention of the operator.  An erroneous or
 malformed Shutdown Communication itself MAY be logged in a hexdump
 format.

5. IANA Considerations

 IANA references this document (in addition to [RFC4486]) for subcodes
 "Administrative Shutdown" (2) and "Administrative Reset" (4) 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
 operators are advised to review Unicode Technical Report #36 [UTR36]
 to learn about these issues.  UTF-8 "Shortest Form" encoding is
 REQUIRED to guard against the technical issues outlined in [UTR36].
 As BGP Shutdown Communications are likely to appear in syslog output,
 there is a risk that carefully constructed Shutdown Communication
 might be formatted by receiving systems in a way to make them appear
 as additional syslog messages.  To limit the ability to mount such an
 attack, the BGP Shutdown Communication is limited to 128 octets in
 length.
 Users of this mechanism should be aware that unless a transport that
 provides integrity is used for the BGP session in question, a
 Shutdown Communication message could be forged.  Unless a transport
 that provides confidentiality 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.  Refer to the
 related considerations in [RFC4271] and [RFC4272].
 Users of this mechanism should consider applying data minimization
 practices as outlined in Section 6.1 of [RFC6973] because a received
 Shutdown Communication may be used at the receiver's discretion.

Snijders, et al. Standards Track [Page 4] RFC 8203 BGP Shutdown July 2017

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,
            <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>.
 [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
            2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
            May 2017, <http://www.rfc-editor.org/info/rfc8174>.

7.2. Informative References

 [RFC4272]  Murphy, S., "BGP Security Vulnerabilities Analysis",
            RFC 4272, DOI 10.17487/RFC4272, January 2006,
            <http://www.rfc-editor.org/info/rfc4272>.
 [RFC5424]  Gerhards, R., "The Syslog Protocol", RFC 5424,
            DOI 10.17487/RFC5424, March 2009,
            <http://www.rfc-editor.org/info/rfc5424>.
 [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
            Morris, J., Hansen, M., and R. Smith, "Privacy
            Considerations for Internet Protocols", RFC 6973,
            DOI 10.17487/RFC6973, July 2013,
            <http://www.rfc-editor.org/info/rfc6973>.
 [UTR36]    Davis, M., Ed. and M. Suignard, Ed., "Unicode Security
            Considerations", Unicode Technical Report #36, August
            2010, <http://unicode.org/reports/tr36/>.

Snijders, et al. Standards Track [Page 5] RFC 8203 BGP Shutdown July 2017

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, Lou Berger, Alvaro Retana, and Adam Roach.
 The authors would like to thank Enke Chen and Vincent Gillet for
 their work on [RFC4486] and granting the related rights to the IETF
 Trust per BCP 78.

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  95134
 United States of America
 Email: jheitz@cisco.com
 John Scudder
 Juniper Networks
 1194 N. Mathilda Ave
 Sunnyvale, CA  94089
 United States of America
 Email: jgs@juniper.net

Snijders, et al. Standards Track [Page 6]

/data/webs/external/dokuwiki/data/pages/rfc/rfc8203.txt · Last modified: 2017/07/26 02:16 by 127.0.0.1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki