IDR J. Snijders
Internet-Draft NTT
Intended status: Standards Track J. Heitz
Expires: May 19, 2017 Cisco
J. Scudder
Juniper
November 15, 2016
The Shutdown Communication BGP Cease Notification Message subcode
draft-snijders-idr-shutdown-00
Abstract
This document defines the BGP Cease NOTIFICATION message "Shutdown
Communication" 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
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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 May 19, 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
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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 TBD "Shutdown Communication" 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
following:
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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 TBD | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... Shutdown Communication ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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.
It is RECOMMENDED that a BGP speaker receiving a Shutdown
Communication observe retry behaviour in line with the RFC4486
[RFC4486] behaviour for "Administrative Shutdown" (sec 4.0).
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 with a reference and reason as to why the BGP session is
shut down. An example of a useful Shutdown Communication would be:
"[VNOC-1-1438367390] software upgrade, back in 2 hours"
"[VNOC-1-1438367390]" is a ticket reference with significance to both
the sender and receiver, followed by a brief human readable message
regarding the work triggering the BGP session shutdown followed by an
indication about the length of the maintenance. The receiver can now
use the string 'VNOC-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 assign a subcode named
"Shutdown Communication" 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. Any implementer
and operator is 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 author would like to gratefully acknowledge Tom Scholl, David
Freedman, and Jared Mauch.
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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