BGP Diagnostic Path Attribute
draft-heitz-idr-diagnostic-attr-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Expired".
|
|
|---|---|---|---|
| Authors | Jakob Heitz , Prasad S. Narasimha , Sameer Gulrajani | ||
| Last updated | 2019-03-11 | ||
| RFC stream | (None) | ||
| Formats | |||
| Additional resources | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-heitz-idr-diagnostic-attr-00
IDR J. Heitz
Internet-Draft P. Narasimha
Intended status: Standards Track S. Gulrajani
Expires: September 11, 2019 Cisco
March 10, 2019
BGP Diagnostic Path Attribute
draft-heitz-idr-diagnostic-attr-00
Abstract
A BGP path attribute for the purpose of network diagnostics is
described. It is non-transitive, such that BGP speakers will not
forward it by default. It is structured as a list of elements. An
element begins with the BGP identifier and AS number of the speaker
that adds the element and includes a list of TLVs. Any speaker can
add or remove an element to/from the list. TLVs for a timestamp and
for a checksum are described.
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 https://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 11, 2019.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
Heitz, et al. Expires September 11, 2019 [Page 1]
Internet-Draft BGP Diagnostic Attribute March 2019
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://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. Data Formats . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1. Timestamp TLV . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Checksum TLV . . . . . . . . . . . . . . . . . . . . . . 4
3. Operational Considerations . . . . . . . . . . . . . . . . . 4
4. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Normative References . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
A BGP path attribute for the purpose of network diagnostics is
described. It is non-transitive, such that BGP speakers will not
propagate it by default. It is structured as a list of elements. An
element begins with the BGP identifier and AS number of the speaker
that adds the element and includes a list of TLVs. Any speaker can
add or remove an element to/from the list. TLVs for a timestamp and
for a checksum are described. The diagnostic attribute may be sent
in a withdraw message.
2. Data Formats
The BGP diagnostic consists of a series of elements, each of which is
formatted as follows.
Heitz, et al. Expires September 11, 2019 [Page 2]
Internet-Draft BGP Diagnostic Attribute March 2019
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BGP Identfifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
+ TLVs +
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields are as follows:
ASN - 4 octet Autonomous System Number of the speaker
that added this element.
BGP Identfifier - BGP Identifier of the speaker that added this
element.
Length - The number of octets comprising this element, If
there were no TLVs included, this length would
be 10.
TLVs - Any number of TLVs as further described. Each
TLV is optional.
2.1. Timestamp TLV
The time at which the indicated speaker created this attribute during
the process of creating to message to be sent. The precision of the
timestamp depends upon the diagnostic application that requires it
and is out of scope of this document.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 1 | Length = 12 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Seconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Fraction |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields are as follows:
Heitz, et al. Expires September 11, 2019 [Page 3]
Internet-Draft BGP Diagnostic Attribute March 2019
Type - 1.
Length - 12.
Seconds - The number of Seconds since 0 h 1 January 1900 UTC as
further described in Section 6 of [RFC5905].
Fraction - A fraction of the above seconds also described in
Section 6 of [RFC5905].
2.2. Checksum TLV
A checksum of the BGP message, including the marker field. The
checksum is only valid between the sending and receiving speaker.
Since a receiving speaker may propagate an update, it will likely
change the set of attributes or their order in its own update
message, thus making the checksum useless in the propagated update.
A BGP speaker MAY remove the checksum TLV from a propagated
Diagnostic Path Attribute.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 2 | Length = 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields are as follows:
Type - 2.
Length - 6.
Checksum - The 16 bit checksum computed according to [RFC1071].
3. Operational Considerations
As with any new BGP attribute, if it is propagated, NLRI packing into
BGP UPDATE messages may be affected. This needs to be taken into
consideration when using the Timestamp TLV to measure bulk update
message timing.
The Checksum TLV is useful to narrow down a source of corruption of
UPDATE messages in each of the software and hardware layers between
the actual BGP processes.
Heitz, et al. Expires September 11, 2019 [Page 4]
Internet-Draft BGP Diagnostic Attribute March 2019
The Diagnostic Path Attribute MAY be sent in an UPDATE message that
does not contain an NLRI field [RFC4271] or an MP_REACH_NLRI Path
Attribute [RFC4760]. When carried in such a message, it is unlikely
to be propagated, although it is possible.
4. Error Handling
A checksum error shall not be treated as a protocol error. The
response is implementation dependent.
A TLV length error shall be treated as attribute-discard according to
[RFC7606].
An unrecognized TLV MUST not be treated as a protocol error.
5. Security Considerations
This attribute is not forwarded by default. Therefore, it should
cause no unexpected ill effects.
6. IANA Considerations
IANA is requested to assign a BGP path attribute value for the BGP
Diagnostic Path Aattribute.
IANA is requested to create and maintain a registry for the TLV
types. The allocation policies as per [RFC8126] are stated for the
range of values.
Range Allocation Policy
----------- ------------------------------
0-32767 First Come First Served
32768-65535 Experimental
Value Description Reference
--------- ------------------------------ ---------
0 Reserved This RFC
1 Timestamp This RFC
2 Checksum This RFC
7. Normative References
[RFC1071] Braden, R., Borman, D., and C. Partridge, "Computing the
Internet checksum", RFC 1071, DOI 10.17487/RFC1071,
September 1988, <https://www.rfc-editor.org/info/rfc1071>.
Heitz, et al. Expires September 11, 2019 [Page 5]
Internet-Draft BGP Diagnostic Attribute March 2019
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[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,
<https://www.rfc-editor.org/info/rfc4271>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.
[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
<https://www.rfc-editor.org/info/rfc5905>.
[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
Patel, "Revised Error Handling for BGP UPDATE Messages",
RFC 7606, DOI 10.17487/RFC7606, August 2015,
<https://www.rfc-editor.org/info/rfc7606>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
Authors' Addresses
Jakob Heitz
Cisco
170 West Tasman Drive
San Jose, CA, CA 95134
USA
Email: jheitz@cisco.com
Prasad S. Narasimha
Cisco
170 West Tasman Drive
San Jose, CA, CA 95134
USA
Email: snprasad@cisco.com
Heitz, et al. Expires September 11, 2019 [Page 6]
Internet-Draft BGP Diagnostic Attribute March 2019
Sameer Gulrajani
Cisco
170 West Tasman Drive
San Jose, CA, CA 95134
USA
Email: sameerg@cisco.com
Heitz, et al. Expires September 11, 2019 [Page 7]