opsawg Z. Li
Internet-Draft China Mobile
Intended status: Standards Track P. Aitken
Expires: January 1, 2018 Brocade Communications Systems, Inc.
June 30, 2017
Extended Length Message Support for IP Flow Information Export (IPFIX)
draft-li-opsawg-ipfix-extended-message-00
Abstract
The specification of the IP Flow Information Export (IPFIX) Protocol
[RFC7011] defines an IPFIX Message length of 16 bits. As new
Information Elements (IEs) are introduced in IPFIX to export long
information, such as the BGP community information
[I-D.ietf-opsawg-ipfix-bgp-community], an IPFIX Message no longer has
sufficient space to fit all the information of a specific flow. This
document updates the IPFIX specification by extending the IPFIX
Message length from 16 bits to 32 bits. For backwards compatibility,
a new version of IPFIX (i.e., 11) is introduced to support the 32-bit
Message length.
Status of This Memo
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This Internet-Draft will expire on January 1, 2018.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. IPFIX Extended Length Message . . . . . . . . . . . . . . . . 3
3.1. IPFIX Extended Length Message Header . . . . . . . . . . 3
3.2. IPFIX Extended Length Set Header . . . . . . . . . . . . 3
3.3. IPFIX Extended Variable-Length IE . . . . . . . . . . . . 4
4. Transport Protocol Considerations . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
The IP Flow Information Export (IPFIX) Protocol [RFC7011] provides
network administrators with traffic flow information using the
Information Elements (IEs) defined in IANA's IPFIX registry
[IANA-IPFIX]. [RFC7011] specifies an IPFIX Message length of 16
bits. As new IEs are introduced in IPFIX to export long information,
such as the BGP community information
[I-D.ietf-opsawg-ipfix-bgp-community], one IPFIX Message no longer
has sufficient space to fit all the information of a specific flow.
The maximum IPFIX message size needs to be extended beyond 65535
octets. This document updates the IPFIX specification by extending
the IPFIX Message length from 16 bits to 32 bits, which means the
maximum IPFIX message size is 4 giga bytes. For backwards
compatibility, a new version of IPFIX (i.e., 11) is introduced to
support the 32-bit Message length.
2. Terminology
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].
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3. IPFIX Extended Length Message
The goal of this document is to allow the export of IPFIX messages up
to 4294967295 (4 giga) octets to satisfy the two situations that may
result in the IPFIX message beyond 65535 octets. One is the IPFIX
message consisting of many small fields where each field is 8-bits or
16-bits long. The other one is the IPFIX message consisting of at
least one IE which is longer than 65535 octets, such as the IEs
defined in [I-D.ietf-opsawg-ipfix-bgp-community].
To satisfy the two situations, this document extends the following
length fields to 32 bits: the Length field in the IPFIX Message
Header, the Length field in the Set Header and the Length field in
the variable-length IE.
3.1. IPFIX Extended Length Message Header
The IPFIX Message Header with a 32 bits length field is called the
IPFIX Extended Length Message Header, whose format is shown in
Figure 1. The version number MUST be 11. The length field is
32-bits long. The meanings and other specifications of the fields in
the Extended Length Message Header are in accordance with [RFC7011].
Please refer to Figure F in [RFC7011].
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Export Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Observation Domain ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: IPFIX Extended Length Message Header Format
3.2. IPFIX Extended Length Set Header
The IPFIX Set Header with a 32 bits length field is called the IPFIX
Extended Length Set Header, whose format is shown in Figure 2. The
meanings and other specifications of the fields in the Extended
Length Set Header are in accordance with [RFC7011]. Please refer to
Figure I in [RFC7011].
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Set ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Extended Length Set Header Format
3.3. IPFIX Extended Variable-Length IE
The Extended Variable-Length IE allows export of variable-length IEs
with size greater than or equal to 65535 octets, the length field of
which is extended to 32 bits as shown in Figure 3. The meanings and
other specifications of the fields in the Extended Variable-Length IE
are in accordance with [RFC7011]. Please refer to Figure S in
[RFC7011].
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
+-+-+-+-+-+-+-+-+
| 255 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length (0 to 4294967295) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IE |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... continuing as needed |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Extended Variable-Length IE
4. Transport Protocol Considerations
As per section 10 of RFC7011, the IPFIX Protocol is transport
protocol independent. SCTP [RFC4960] using the Partially Reliable
SCTP (PR-SCTP) extension as specified in [RFC3758] MUST be
implemented by all compliant implementations. UDP [RFC768] MAY also
be implemented by compliant implementations. TCP [RFC793] MAY also
be implemented by compliant implementations. The Collecting Process
of a compliant implementation supporting IPFIX Extended Length
Message MUST be able to handle IPFIX Message lengths of up to
4294967295 octets.
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5. Security Considerations
This extension to IPFIX does not change IPFIX's underlying security
issues, please refer to RFC7011.
6. IANA Considerations
A new IPFIX Version Number value of 11 is reserved in IANA's IPFIX
registry [IANA-IPFIX] for the IPFIX Extended Length Message specified
in this document.
7. Acknowledgements
The authors would like to thank Ignas Bagdonas and Stewart Bryant for
their constructive discussion.
8. References
8.1. Normative References
[IANA-IPFIX]
IANA, "IPFIX Information Elements registry",
<http://www.iana.org/assignments/ipfix/ipfix.xml>.
[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>.
[RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
"Specification of the IP Flow Information Export (IPFIX)
Protocol for the Exchange of Flow Information", STD 77,
RFC 7011, DOI 10.17487/RFC7011, September 2013,
<http://www.rfc-editor.org/info/rfc7011>.
8.2. Informative References
[]
Li, Z., Gu, R., and J. Dong, "Export BGP community
information in IP Flow Information Export (IPFIX)", draft-
ietf-opsawg-ipfix-bgp-community-02 (work in progress),
June 2017.
[RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.
Conrad, "Stream Control Transmission Protocol (SCTP)
Partial Reliability Extension", RFC 3758,
DOI 10.17487/RFC3758, May 2004,
<http://www.rfc-editor.org/info/rfc3758>.
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[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
RFC 4960, DOI 10.17487/RFC4960, September 2007,
<http://www.rfc-editor.org/info/rfc4960>.
Authors' Addresses
Zhenqiang Li
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing 100053
China
Email: li_zhenqiang@hotmail.com
Paul Aitken
Brocade Communications Systems, Inc.
19a Canning Street, Level 3
Edinburgh, Scotland EH3 8EG
United Kingdom
Email: paitken@brocade.com
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