Internet DRAFT - draft-ietf-ipfix-information-model-rfc5102bis
draft-ietf-ipfix-information-model-rfc5102bis
Network Working Group B. Claise, Ed.
Internet Draft Cisco Systems, Inc.
Obsoletes: 5102 B. Trammell, Ed.
Category: Standards Track ETH Zurich
Expires: August 16, 2013 February 12, 2013
Information Model for IP Flow Information eXport (IPFIX)
draft-ietf-ipfix-information-model-rfc5102bis-10.txt
Abstract
This document defines the datatypes and management policy for the
information model for the IP Flow Information eXport (IPFIX)
protocol. This information model is maintained as the IANA IPFIX
Information Element Registry, the initial contents of which were
defined by RFC 5102. This information model is used by the IPFIX
Protocol for encoding measured traffic information and information
related to the traffic Observation Point, the traffic Metering
Process, and the Exporting Process. Although developed for the IPFIX
Protocol, the model is defined in an open way that easily allows
using it in other protocols, interfaces, and applications. This
document obsoletes RFC 5102.
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 August 16, 2013.
Copyright Notice
Copyright (c) 2013 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Changes since RFC 5102 . . . . . . . . . . . . . . . . . . 4
1.2. IPFIX Documents Overview . . . . . . . . . . . . . . . . . 4
2. Properties of IPFIX Protocol Information Elements . . . . . . 5
2.1. Information Element Specification Template . . . . . . . . 5
2.2. Scope of Information Elements . . . . . . . . . . . . . . 7
2.3. Naming Conventions for Information Elements . . . . . . . 7
3. Type Space . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1. Abstract Data Types . . . . . . . . . . . . . . . . . . . 8
3.1.1. unsigned8 . . . . . . . . . . . . . . . . . . . . . . 9
3.1.2. unsigned16 . . . . . . . . . . . . . . . . . . . . . . 9
3.1.3. unsigned32 . . . . . . . . . . . . . . . . . . . . . . 9
3.1.4. unsigned64 . . . . . . . . . . . . . . . . . . . . . . 9
3.1.5. signed8 . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.6. signed16 . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.7. signed32 . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.8. signed64 . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.9. float32 . . . . . . . . . . . . . . . . . . . . . . . 10
3.1.10. float64 . . . . . . . . . . . . . . . . . . . . . . . 10
3.1.11. boolean . . . . . . . . . . . . . . . . . . . . . . . 10
3.1.12. macAddress . . . . . . . . . . . . . . . . . . . . . 10
3.1.13. octetArray . . . . . . . . . . . . . . . . . . . . . 10
3.1.14. string . . . . . . . . . . . . . . . . . . . . . . . 10
3.1.15. dateTimeSeconds . . . . . . . . . . . . . . . . . . . 10
3.1.16. dateTimeMilliseconds . . . . . . . . . . . . . . . . 10
3.1.17. dateTimeMicroseconds . . . . . . . . . . . . . . . . 10
3.1.18. dateTimeNanoseconds . . . . . . . . . . . . . . . . . 11
3.1.19. ipv4Address . . . . . . . . . . . . . . . . . . . . . 11
3.1.20. ipv6Address . . . . . . . . . . . . . . . . . . . . . 11
3.1.21. basicList . . . . . . . . . . . . . . . . . . . . . . 11
3.1.22. subTemplateList . . . . . . . . . . . . . . . . . . . 11
3.1.23. subTemplateMultiList . . . . . . . . . . . . . . . . 11
3.2. Data Type Semantics . . . . . . . . . . . . . . . . . . . 11
3.2.1. quantity . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.2. totalCounter . . . . . . . . . . . . . . . . . . . . . 12
3.2.3. deltaCounter . . . . . . . . . . . . . . . . . . . . . 12
3.2.4. identifier . . . . . . . . . . . . . . . . . . . . . . 12
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3.2.5. flags . . . . . . . . . . . . . . . . . . . . . . . . 12
4. Information Element Identifiers . . . . . . . . . . . . . . . 13
5. Information Elements . . . . . . . . . . . . . . . . . . . . . 13
6. Extending the Information Model . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7.1. IPFIX Information Elements . . . . . . . . . . . . . . . . 16
7.2. MPLS Label Type Identifier . . . . . . . . . . . . . . . . 16
7.3. XML Namespace and Schema . . . . . . . . . . . . . . . . . 17
7.4. Addition, Revision, and Deprecation . . . . . . . . . . . 17
8. Security Considerations . . . . . . . . . . . . . . . . . . . 18
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.1. Normative References . . . . . . . . . . . . . . . . . . 19
10.2. Informative References . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
Contributors' Addresses . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction
The IP Flow Information eXport (IPFIX) protocol serves for
transmitting information related to network traffic measurement. The
protocol specification in [RFC5101bis] defines how Information
Elements are transmitted. For Information Elements, it specifies the
encoding of a set of basic data types. However, the list of
Information Elements that can be transmitted by the protocol, such as
Flow attributes (source IP address, number of packets, etc.) and
information about the Metering and Exporting Process (packet
Observation Point, sampling rate, Flow timeout interval, etc.), is
not specified in [RFC5101bis].
The IANA IPFIX Information Element registry [IPFIX-IANA] is the
current complete reference for IPFIX Information Elements. The
initial values for this registry were provided by [RFC5102].
This document complements the IPFIX protocol specification
[RFC5101bis] by providing an overview of the IPFIX information model
and specifying data types for it. IPFIX-specific terminology used in
this document is defined in Section 2 of [RFC5101bis]. As in
[RFC5101bis], these IPFIX-specific terms have the first letter of a
word capitalized when used in this document.
The use of the term 'information model' is not fully in line with the
definition of this term in [RFC3444], as the IPFIX information model
does not specify relationships between Information Elements. Nor does
the IPFIX information model specify a concrete encoding of
Information Elements; for an encoding suitable for use with the IPFIX
protocol, see [RFC5101bis]. Besides the encoding used by the IPFIX
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protocol, other encodings of IPFIX Information Elements can be
applied, for example, XML-based encodings.
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].
1.1. Changes since RFC 5102
This document obsoletes the Proposed Standard revision of the IPFIX
Protocol Specification [RFC5102]. The following changes have been
made to this document with respect to the previous document:
- All outstanding technical and editorial errata filed on the
[RFC5102] as of publication time have been corrected.
- All references into [RFC5101] have been updated to [RFC5101bis],
reflecting changes in that document as necessary.
- Information element definitions have been removed, as the
reference for these is now [IPFIX-IANA]; a historical note on
categorizations of information elements as defined in [RFC5102] has
been retained in section 5.
- The process for modifying [IPFIX-IANA] has been improved, and is
now described in [IPFIX-IE-DOCTORS]; Section 6 has been updated
accordingly, and a new section 7.3 gives IANA considerations for this
process.
- Definitions of timestamp data types have been clarified.
- Appendices A and B have been removed
1.2. IPFIX Documents Overview
The IPFIX protocol provides network administrators with access to
network flow information. The architecture for the export of
measured flow information out of an IPFIX Exporting Process to a
Collecting Process is defined in [RFC5470], per the requirements
defined in [RFC3917]. The IPFIX Protocol Specification [RFC5101bis]
defines how IPFIX data records and templates are carried via a number
of transport protocols from IPFIX Exporting Processes to IPFIX
Collecting Processes.
Four IPFIX optimizations/extensions are currently specified: a
bandwidth saving method for the IPFIX protocol in [RFC5473], an
efficient method for exporting bidirectional flows in [RFC5103], a
method for the definition and export of complex data structures in
[RFC6313], and the specification of the Protocol for IPFIX Mediations
[IPFIX-MED-PROTO] based on the IPFIX Mediation Framework [RFC6183].
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IPFIX has a formal description of IPFIX Information Elements, their
name, type and additional semantic information, as specified in this
document, with the export of the Information Element types specified
in [RFC5610].
[RFC6728] specifies a data model for configuring and monitoring IPFIX
and PSAMP compliant devices using the NETCONF protocol, while
[RFC6615] specifies a MIB module for monitoring.
In terms of development, [RFC5153] provides guidelines for the
implementation and use of the IPFIX protocol, while [RFC5471]
provides guidelines for testing.
Finally, [RFC5472] describes what type of applications can use the
IPFIX protocol and how they can use the information provided. It
furthermore shows how the IPFIX framework relates to other
architectures and frameworks.
2. Properties of IPFIX Protocol Information Elements
2.1. Information Element Specification Template
Information in messages of the IPFIX protocol is modeled in terms of
Information Elements of the IPFIX information model. The IPFIX
Information Elements mentioned in Section 5 are specified in [IPFIX-
IANA].
All Information Elements specified for the IPFIX protocol MUST have
the following properties defined.
name - A unique and meaningful name for the Information Element.
elementId - A numeric identifier of the Information Element. If this
identifier is used without an enterprise identifier (see
[RFC5101bis] and enterpriseId below), then it is globally unique
and the list of allowed values is administered by IANA. It is
used for compact identification of an Information Element when
encoding Templates in the protocol.
description - The semantics of this Information Element. Describes
how this Information Element is derived from the Flow or other
information available to the observer. Information Elements of
dataType string or octetArray which have length constraints (fixed
length, minimum and/or maximum length) MUST note these constraints
in their description.
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dataType - One of the types listed in Section 3.1 of this document or
registered in the IANA IPFIX Information Element Data Types
registry. The type space for attributes is constrained to
facilitate implementation. The existing type space encompasses
most primitive types used in modern programming languages, as well
as some derived types (such as ipv4Address) that are common to
this domain.
status - The status of the specification of this Information Element.
Allowed values are 'current' and 'deprecated'. All newly-defined
Information Elements have 'current' status. The process for moving
Information Elements to the 'deprecated' status is defined in
Section 5.2 of [IPFIX-IE-DOCTORS].
Enterprise-specific Information Elements MUST have the following
property defined:
enterpriseId - Enterprises may wish to define Information Elements
without registering them with IANA, for example, for
enterprise-internal purposes. For such Information Elements, the
Information Element identifier described above is not sufficient
when the Information Element is used outside the enterprise. If
specifications of enterprise-specific Information Elements are
made public and/or if enterprise-specific identifiers are used by
the IPFIX protocol outside the enterprise, then the
enterprise-specific identifier MUST be made globally unique by
combining it with an enterprise identifier. Valid values for the
enterpriseId are defined by IANA as Structure of Management
Information (SMI) network management private enterprise numbers,
defined at [PEN-IANA].
All Information Elements specified for the IPFIX protocol either in
this document or by any future extension MAY have the following
properties defined:
dataTypeSemantics - The integral types are qualified by additional
semantic details. Valid values for the data type semantics are
specified in Section 3.2 of this document or in a future extension
of the information model.
units - If the Information Element is a measure of some kind, the
units identify what the measure is.
range - Some Information Elements may only be able to take on a
restricted set of values that can be expressed as a range (e.g., 0
through 511 inclusive). If this is the case, the valid inclusive
range SHOULD be specified; values for this Information Element
outside the range are invalid and MUST NOT be exported.
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reference - Identifies additional specifications that more precisely
define this item or provide additional context for its use.
The following two Information Element properties are defined to allow
the management of an Information Element registry with Information
Element definitions that may be updated over time, per the process
defined in Section 5.2 of [IPFIX-IE-DOCTORS].
revision - The revision number of an Information Element, starting at
0 for Information Elements at time of definition, and incremented
by one for each revision.
date - The date of the entry of this revision of the Information
Element into the registry.
A template for specifying Information Elements in Internet-Drafts is
given in Section 9.1 of [IPFIX-IE-DOCTORS], and an XML Schema for
specifying Information Elements in the IANA IPFIX registry [IPFIX-
IANA] at [IPFIX-XML-SCHEMA].
2.2. Scope of Information Elements
By default, most Information Elements have a scope specified in their
definitions. Within Data Records defined by Option Templates, the
IPFIX protocol allows further limiting of the Information Element
scope. The new scope is specified by one or more scope fields and
defined as the combination of all specified scope values; see Section
3.4.2.1 on IPFIX scopes in [RFC5101bis].
2.3. Naming Conventions for Information Elements
The following naming conventions were used for naming Information
Elements in this document. It is recommended that extensions of the
model use the same conventions.
o Names of Information Elements SHOULD be descriptive.
o Names of Information Elements MUST be unique within the IANA IPFIX
registry [IPFIX-IANA]. Enterprise-specific Information Elements
SHOULD be prefixed with a vendor name.
o Names of Information Elements MUST start with non-capitalized
letters.
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o Composed names MUST use capital letters for the first letter of
each component (except for the first one). All other letters are
non-capitalized, even for acronyms. Exceptions are made for
acronyms containing non-capitalized letters, such as 'IPv4' and
'IPv6'. Examples are sourceMacAddress and destinationIPv4Address.
o Middleboxes [RFC3234] may change Flow properties, such as the
Differentiated Service Code Point (DSCP) value or the source IP
address. If an IPFIX Observation Point is located in the path of
a Flow before one or more middleboxes that potentially modify
packets of the Flow, then it may be desirable to also report Flow
properties after the modification performed by the middleboxes.
An example is an Observation Point before a packet marker changing
a packet's IPv4 Type of Service (TOS) field that is encoded in
Information Element ipClassOfService. Then the value observed and
reported by Information Element ipClassOfService is valid at the
Observation Point, but not after the packet passed the packet
marker. For reporting the change value of the TOS field, the
IPFIX information model uses Information Elements that have a name
prefix "post", for example, "postIpClassOfService". Information
Elements with prefix "post" report on Flow properties that are not
necessarily observed at the Observation Point, but which are
obtained within the Flow's Observation Domain by other means
considered to be sufficiently reliable, for example, by analyzing
the packet marker's marking tables.
3. Type Space
This section describes the abstract data types that can be used for
the specification of IPFIX Information Elements in Section 4.
Section 3.1 describes the set of abstract data types.
Abstract data types unsigned8, unsigned16, unsigned32, unsigned64,
signed8, signed16, signed32, and signed64 are integral data types.
As described in Section 3.2, their data type semantics can be further
specified, for example, by 'totalCounter', 'deltaCounter',
'identifier', or 'flags'.
3.1. Abstract Data Types
This section describes the set of valid abstract data types of the
IPFIX information model, independent of encoding. Note that further
abstract data types may be specified by future updates to this
document. Changes to the associated IPFIX Information Element Data
Types subregistry [IPFIX-IANA] specified in [RFC5610] require a
Standards Action [RFC5226].
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The current encodings of these data types for use with the IPFIX
protocol is defined in [RFC5101bis]; encodings allowing the use of
the IPFIX Information Elements [IPFIX-IANA] with other protocols may
be defined in the future by referencing this document.
3.1.1. unsigned8
The type "unsigned8" represents a non-negative integer value in the
range of 0 to 255.
3.1.2. unsigned16
The type "unsigned16" represents a non-negative integer value in the
range of 0 to 65535.
3.1.3. unsigned32
The type "unsigned32" represents a non-negative integer value in the
range of 0 to 4294967295.
3.1.4. unsigned64
The type "unsigned64" represents a non-negative integer value in the
range of 0 to 18446744073709551615.
3.1.5. signed8
The type "signed8" represents an integer value in the range of -128
to 127.
3.1.6. signed16
The type "signed16" represents an integer value in the range of
-32768 to 32767.
3.1.7. signed32
The type "signed32" represents an integer value in the range of
-2147483648 to 2147483647.
3.1.8. signed64
The type "signed64" represents an integer value in the range of
-9223372036854775808 to 9223372036854775807.
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3.1.9. float32
The type "float32" corresponds to an IEEE single-precision 32-bit
floating point type as defined in [IEEE.754.1985].
3.1.10. float64
The type "float64" corresponds to an IEEE double-precision 64-bit
floating point type as defined in [IEEE.754.1985].
3.1.11. boolean
The type "boolean" represents a binary value. The only allowed
values are "true" and "false".
3.1.12. macAddress
The type "macAddress" represents a MAC-48 address as in
[IEEE.802-3.2002].
3.1.13. octetArray
The type "octetArray" represents a finite-length string of octets.
3.1.14. string
The type "string" represents a finite-length string of valid
characters from the Unicode coded character set [ISO.10646]. Unicode
incorporates ASCII [RFC20] and the characters of many other
international character sets.
3.1.15. dateTimeSeconds
The data type "dateTimeSeconds" represents a time value expressed
with second-level precision.
3.1.16. dateTimeMilliseconds
The data type "dateTimeMilliseconds" represents a time value
expressed with millisecond-level precision.
3.1.17. dateTimeMicroseconds
The type "dateTimeMicroseconds" represents a time value expressed
with microsecond-level precision.
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3.1.18. dateTimeNanoseconds
The type "dateTimeNanoseconds" represents a time value expressed with
nanosecond-level precision.
3.1.19. ipv4Address
The type "ipv4Address" represents an IPv4 address.
3.1.20. ipv6Address
The type "ipv6Address" represents an IPv6 address.
3.1.21. basicList
The type "basicList" supports structured data export as described in
[RFC6313]; see section 4.5.1 of that document for encoding details.
3.1.22. subTemplateList
The type "subTemplateList" supports structured data export as
described in [RFC6313]; see section 4.5.2 of that document for
encoding details.
3.1.23. subTemplateMultiList
The type "subTemplateMultiList" supports structured data export as
described in [RFC6313]; see section 4.5.3 of that document for
encoding details.
3.2. Data Type Semantics
This section describes the set of valid data type semantics of the
IPFIX information model. A sub-registry of data type semantics
[IPFIX-IANA] is established in [RFC5610]; the restrictions on the use
of semantics below are compatible with those specified in section
3.10 of that document. These semantics apply only to numeric types,
as noted in the description of each semantic below.
Further data type semantics may be specified by future updates to
this document. Changes to the associated IPFIX Information Element
Semantics sub-registry [IPFIX-IANA] require a Standards Action
[RFC5226].
3.2.1. quantity
A numeric (integral or floating point) value representing a measured
value pertaining to the record. This is distinguished from counters
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that represent an ongoing measured value whose "odometer" reading is
captured as part of a given record. This is the default semantic type
of all numeric data types.
3.2.2. totalCounter
An integral value reporting the value of a counter. Counters are
unsigned and wrap back to zero after reaching the limit of the type.
For example, an unsigned64 with counter semantics will continue to
increment until reaching the value of 2**64 - 1. At this point, the
next increment will wrap its value to zero and continue counting from
zero. The semantics of a total counter is similar to the semantics of
counters used in SNMP, such as Counter32 defined in [RFC2578]. The
only difference between total counters and counters used in SNMP is
that the total counters have an initial value of 0. A total counter
counts independently of the export of its value.
3.2.3. deltaCounter
An integral value reporting the value of a counter. Counters are
unsigned and wrap back to zero after reaching the limit of the type.
For example, an unsigned64 with counter semantics will continue to
increment until reaching the value of 2**64 - 1. At this point, the
next increment will wrap its value to zero and continue counting from
zero. The semantics of a delta counter is similar to the semantics of
counters used in SNMP, such as Counter32 defined in RFC 2578
[RFC2578]. The only difference between delta counters and counters
used in SNMP is that the delta counters have an initial value of 0. A
delta counter is reset to 0 each time it is exported and/or expires
without export.
3.2.4. identifier
An integral value that serves as an identifier. Specifically,
mathematical operations on two identifiers (aside from the equality
operation) are meaningless. For example, Autonomous System ID 1 *
Autonomous System ID 2 is meaningless. Identifiers MUST be one of the
signed or unsigned data types.
3.2.5. flags
An integral value that represents a set of bit fields. Logical
operations are appropriate on such values, but not other mathematical
operations. Flags MUST always be of an unsigned data type.
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4. Information Element Identifiers
All Information Elements defined in the IANA IPFIX Information
Element registry [IPFIX-IANA] have their identifiers assigned by
IANA.
The value of these identifiers is in the range of 1-32767. Within
this range, Information Element identifier values in the sub-range of
1-127 are compatible with field types used by NetFlow version 9
[RFC3954] for historical reasons.
In general, IANA will add newly registered Information Elements to
the registry, assigning the lowest available Information Element
identifier in the range 128-32767.
Enterprise-specific Information Element identifiers have the same
range of 1-32767, but they are coupled with an additional enterprise
identifier. For enterprise-specific Information Elements, Information
Element identifier 0 is also reserved. Enterprise-specific
Information Element identifiers can be chosen by an enterprise
arbitrarily within the range of 1-32767. The same identifier may be
assigned by other enterprises for different purposes; these
Information Elements are distinct because the Information Element
identifier is coupled with an enterprise identifier.
Enterprise identifiers are to be registered as SMI network management
private enterprise code numbers with IANA. The registry can be found
at [PEN-IANA].
5. Information Elements
[IPFIX-IANA] is now the normative reference for IPFIX Information
Elements. At the time of publication of [RFC5102], this section
defined the initial contents of that registry.
As a historical note, Information Elements were organized into
categories in [RFC5102] according to their semantics and their
applicability; these categories were not carried forward into [IPFIX-
IANA] as an organizing principle. The categories (with example IEs)
were:
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1. Identifiers (e.g. ingressInterface)
2. Metering and Exporting Process Configuration
(e.g. exporterIPv4Address)
3. Metering and Exporting Process Statistics
(e.g. exportedOctetTotalCount)
4. IP Header Fields (e.g. sourceIPv4Address)
5. Transport Header Fields (e.g. sourceTransportPort)
6. Sub-IP Header Fields (e.g. sourceMacAddress)
7. Derived Packet Properties (e.g. bgpSourceAsNumber)
8. Min/Max Flow Properties (e.g. minimumIpTotalLength)
9. Flow Timestamps (e.g. flowStartTimeMilliseconds)
10. Per-Flow Counters (e.g. octetDeltaCount)
11. Miscellaneous Flow Properties (e.g. flowEndReason)
12. Padding (paddingOctets)
Information Elements derived from fields of packets or from packet
treatment can typically serve as Flow Keys used for mapping packets
to Flows. These Information Elements were placed in categories 4-7 in
the original categorization.
Information Elements not serving as Flow Keys may have different
values for each packet in a Flow. For Information Elements with
values derived from packets fields or packet treatment, and for which
the value may change from packet to packet within a single Flow, the
exported value of an Information Element is by default determined by
the first packet observed for the corresponding Flow; the description
of the Information Element may however explicitly specify different
semantics. This simple rule allows writing all Information Elements
related to header fields once when the first packet of the Flow is
observed. For further observed packets of the same Flow, only Flow
properties that depend on more than one packet need to be updated;
these Information Elements were placed in categories 8-11 in the
original categorization.
Information Elements with a name having the "post" prefix (e.g.
postIpClassOfService), do not necessarily report properties that were
actually observed at the Observation Point, but may be retrieved by
other means within the Observation Domain. These Information Elements
can be used if there are middlebox functions within the Observation
Domain changing Flow properties after packets passed the Observation
Point; they may also be reported directly by the Observation Point if
the Observation Point is situated such as to observe packets on both
sides of the middlebox.
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6. Extending the Information Model
A key requirement for IPFIX is to allow for extension of the
Information Model via the IANA IPFIX registry [IPFIX-IANA]. New
Information Element definitions can be added to this registry subject
to an Expert Review [RFC5226], with additional process considerations
decribed in [IPFIX-IE-DOCTORS]; that document also provides
guidelines for authors and reviewers of new Information Element
definitions.
For new Information Elements, the type space defined in Section 3 can
be used. If required, new abstract data types can be added to the
data type subregistry [IPFIX-IANA] defined in [RFC5610]. New abstract
data types and semantics are subject to Standards Action [RFC5226],
and MUST be defined in IETF Standards Track documents updating this
document.
Enterprises may wish to define Information Elements without
registering them with IANA. IPFIX explicitly supports
enterprise-specific Information Elements. Enterprise-specific
Information Elements are described in Sections 2.1 and 4; guidelines
for using them appear in [IPFIX-IE-DOCTORS].
7. IANA Considerations
As this document obsoletes [RFC5102], upon publication of this
document, IANA will update the Reference to the IPFIX Information
Element registry [IPFIX-IANA], the IPFIX MPLS Label Type subregistry
of that registry, the urn:ietf:params:xml:ns:ipfix-info XML
namespace, and the urn:ietf:params:xml:schema:ipfix-info XML schema
to refer to this document.
However, [RFC5102] still provides a historical reference for the
initial entries in the IPFIX Information Element registry. Therefore,
IANA will keep [RFC5102] as the Requestor of those Information
Elements in the IPFIX Information Element registry which list
[RFC5102] as their Requestor, and add the following explanatory note
to the IPFIX Information Element registry upon publication of this
document:
"RFC XXXX has obsoleted RFC 5102; references to RFC 5102 in this
registry remain as part of the historical record."
The Information Element Specification Template in Section 2.1
contains two new columns not present in [RFC5102]. On publication of
this document, IANA will create a new Revision column in the IPFIX
Information Element Registry, and set the Revision of existing
Information Elements to 0. IANA will also create a new Date column in
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the IPFIX Information Element Registry, and set the Date of all
existing Information Elements to the publication date of this
document.
To identify Information Elements with identifiers 127 or below as
NetFlow v9 [RFC3954] compatible, upon publication of this document,
IANA will set the Name of all existing Reserved Information Elements
with identifier 127 or less to "Assigned for NetFlow v9
compatibility", and the Reference of those Information Elements to
[RFC3954].
As IANA now has change control of the schema used for the IANA IPFIX
Information Element Registry [IPFIX-IANA], IANA will deprecate the
previous XML Schema for the description of Information Elements
urn:ietf:params:xml:schema:ipfix-info [IPFIX-XML-SCHEMA].
To support the process described in Section 7.4, IANA will establish
a mailing list for communicating with the IE-DOCTORS experts, named
ie-doctors@ietf.org.
The remaining subsections of this section contain no actions for
IANA.
7.1. IPFIX Information Elements
This document refers to Information Elements, for which the Internet
Assigned Numbers Authority (IANA) has created the IPFIX Information
Element Registry [IPFIX-IANA]. The columns of this registry must at
minimum be able to store the information defined in the template in
Section 2.1; it may contain other information as necessary for the
management of the registry.
The process for making additions or other changes to the IPFIX
Information Element Registry is given in Section 7.4.
7.2. MPLS Label Type Identifier
Information Element #46, named mplsTopLabelType, carries MPLS label
types. Values for 5 different types have initially been defined.
For ensuring extensibility of this information, IANA has created a
new subregistry for MPLS label types and filled it with the initial
list from the description Information Element #46, mplsTopLabelType.
New assignments for MPLS label types are administered by IANA through
Expert Review [RFC5226], i.e., review by one of a group of experts
designated by an IETF Area Director. The group of experts must
double check the label type definitions with already defined label
types for completeness, accuracy, and redundancy. The specification
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of new MPLS label types MUST be published using a well-established
and persistent publication medium.
7.3. XML Namespace and Schema
The prior version of this document [RFC5102] specified an XML schema
for IPFIX Information Element definitions [IPFIX-XML-SCHEMA], which
was used in the generation of the document text itself. When the IANA
IPFIX Information Element registry [IPFIX-IANA] was created, change
control on the registry and the schema used to validate it passed to
IANA.
The use of a machine-readable syntax for the registry enables the
creation of IPFIX tools that can automatically adapt to extensions to
the information model. It should be noted that the use of XML in
Exporters, Collectors, or other tools is not mandatory for the
deployment of IPFIX. In particular, Exporting Processes do not
produce or consume XML as part of their operation. IPFIX Collectors
MAY take advantage of the machine-readability of the information
model vs. hard coding their behavior or inventing proprietary means
for accommodating extensions. However, Collectors SHOULD NOT poll the
IANA registry [IPFIX-IANA] directly at runtime, in order to avoid
unnecessary load on the IANA infrastructure serving the registry.
The reference to the current schema is embedded in the registry
[IPFIX-IANA]; this schema may change from time to time as necessary
to support the maintenance of the registry. As such, the schema
urn:ietf:params:xml:schema:ipfix-info [IPFIX-XML-SCHEMA] specified in
[RFC5102] has been deprecated.
7.4. Addition, Revision, and Deprecation
New assignments for IPFIX Information Elements are administered by
IANA through Expert Review [RFC5226]. These experts are referred to
as IE-DOCTORS experts, and are appointed by the IESG. The process
they follow is defined in [IPFIX-IE-DOCTORS].
Information Element identifiers in the range 1-127 are compatible
with field types used by NetFlow version 9 [RFC3954] for historical
reasons, and must not be assigned unless the Information Element is
compatible with the NetFlow version 9 protocol, as determined by an
IE-DOCTORS expert designated by the IESG as a Netflow version 9
expert.
Future assignments added to the IPFIX Information Element Registry
which require subregistries for enumerated values (e.g. section 7.2,
below) must have those subregistries added simultaneously with the
new assignment; additions to these subregistries must be subject to
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Expert Review [RFC5226]. Unless specified at assignment time, the
experts for the subregistry will be the same as for the Information
Element registry as a whole.
When IANA receives a request to add, revise, or deprecate an
Information Element in the IPFIX Information Elements Registry, it
forwards the request to the IE-DOCTORS experts for review.
When IANA receives an approval for a request to add an Information
Element definition from the IE-DOCTORS experts, it adds that
Information Element to the registry. The approved request may include
changes made by the requestor and/or reviewers as compared to the
original request.
When IANA receives an approval for a request to revise an Information
Element definition from the IE-DOCTORS experts, it changes that
Information Element's definition in the registry, and updates the
Revision and Date columns as appropriate. The approved request may
include changes from the original request. If the original
Information Element was added to the registry with IETF consensus
(i.e., was defined by an RFC), the revision will require IETF
consensus as well.
When IANA receives an approval for a request to deprecate an
Information Element definition from the IE-DOCTORS experts, it
changes that Information Element's definition in the registry, and
updates the Revision and Date columns as appropriate. The approved
request may include changes from the original request. If the
original Information Element was added to the registry with IETF
consensus (i.e., was defined by an RFC), the deprecation will require
IETF consensus as well.
8. Security Considerations
The IPFIX information model itself does not directly introduce
security issues. Rather, it defines a set of attributes that may for
privacy or business issues be considered sensitive information.
For example, exporting values of header fields may make attacks
possible for the receiver of this information, which would otherwise
only be possible for direct observers of the reported Flows along the
data path.
The underlying protocol used to exchange the information described
here must therefore apply appropriate procedures to guarantee the
integrity and confidentiality of the exported information. These
protocols are defined in separate documents, specifically the IPFIX
protocol document [RFC5101bis].
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9. Acknowledgements
This document is substantially based on [RFC5102]; the editors thank
the authors of that document, listed below as contributors. Special
thanks to Paul Aitken, for the detailed review.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC6313] Claise, B., Dhandapani, G., Aitken, P, and S. Yates,
"Export of Structured Data in IP Flow Information Export
(IPFIX)", RFC6313, July 2011.
[RFC5101bis]
Claise, B., and B. Trammell, Editors, "Specification of
the IP Flow Information eXport (IPFIX) Protocol for the
Exchange of IP Traffic Flow Information", draft-ietf-
ipfix-protocol-rfc5101bis-04, Work in Progress, December
2012.
[IPFIX-IE-DOCTORS]
Trammell, B., and B. Claise, "Guidelines for Authors and
Reviewers of IPFIX Information Elements", draft-ietf-
ipfix-ie-doctors-07, Work in Progress, October 2012.
10.2. Informative References
[IEEE.802-3.2002]
Insitute of Electrical and Electronics Engineers,
"Information technology - Telecommunications and
information exchange between systems - Local and
metropolitan area networks - Specific requirements - Part
3: Carrier sense multiple access with collision detection
(CSMA/CD) access method and physical layer
specifications", IEEE Standard 802.3, September 2002.
[IEEE.754.1985]
Institute of Electrical and Electronics Engineers,
"Standard for Binary Floating-Point Arithmetic", IEEE
Standard 754, August 1985.
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Internet-Draft IPFIX Information Model February 12, 2013
[ISO.10646]
International Organization for Standardization,
"Information technology - Universal Coded Character Set
(UCS)", ISO/IEC 10646:2012(E), June 2012.
[RFC20]
V. Cerf, "ASCII format for Network Interchange", RFC 20,
October 1969.
[RFC2578] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Structure of Management Information Version 2 (SMIv2)",
STD 58, RFC 2578, April 1999.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999.
[RFC3234] Carpenter, B. and S. Brim, "Middleboxes: Taxonomy and
Issues", RFC 3234, February 2002.
[RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between
Information Models and Data Models", RFC 3444, January
2003.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC3917] Quittek, J., Zseby, T., Claise, B., and S. Zander,
"Requirements for IP Flow Information Export (IPFIX)", RFC
3917, October 2004.
[RFC3954] Claise, B., Ed., "Cisco Systems NetFlow Services Export
Version 9", RFC 3954, October 2004.
[RFC5101] Claise, B., Bryant, S., Leinen, S., Dietz, T., and
Trammell, B., "Specification of the IPFIX Protocol for the
Exchange of IP Traffic Flow Information", RFC 5101,
January 2008.
[RFC5102] Quittek, J., Bryant, S. Claise, B., Aitken, P., and Meyer,
J., "Information Model for IP Flow Information Export",
RFC 5102, January 2008.
[RFC5103] Trammell, B., and E. Boschi, "Bidirectional Flow Export
Using IP Flow Information Export (IPFIX)", RFC 5103,
January 2008.
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[RFC5153] Boschi, E., Mark, L., Quittek J., and P. Aitken, "IP Flow
Information Export (IPFIX) Implementation Guidelines",
RFC5153, April 2008.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC5470] Sadasivan, G., Brownlee, N., Claise, B., and J. Quittek,
"Architecture for IP Flow Information Export", RFC5470,
March 2009.
[RFC5471] Schmoll, C., Aitken, P., and B. Claise, "Guidelines for IP
Flow Information Export (IPFIX) Testing", RFC5471, March
2009.
[RFC5472] Zseby, T., Boschi, E., Brownlee, N., and B. Claise, "IP
Flow Information Export (IPFIX) Applicability", RFC5472,
March 2009.
[RFC5473] Boschi, E., Mark, L., and B. Claise, "Reducing Redundancy
in IP Flow Information Export (IPFIX) and Packet Sampling
(PSAMP) Reports", RFC5473, March 2009.
[RFC5610] Boschi, E., Trammell, B., Mark, L., and T. Zseby,
"Exporting Type Information for IP Flow Information Export
(IPFIX) Information Elements", July 2009.
[RFC6183] Kobayashi, A., Claise, B., Muenz, G, and K. Ishibashi, "IP
Flow Information Export (IPFIX) Mediation: Framework",
RFC6183, April 2011.
[RFC6615]
Dietz, T., Kobayashi, A., Claise, B., and G. Muenz,
"Definitions of Managed Objects for IP Flow Information
Export", RFC6615, June 2012.
[RFC6728]
Muenz, G., Claise, B., and P. Aitken, "Configuration Data
Model for IPFIX and PSAMP", RFC 6728, October 2012.
[IPFIX-MED-PROTO]
Claise, B., Kobayashi, A., and B. Trammell, "Operation of
the IP Flow Information Export (IPFIX) Protocol on IPFIX
Mediators", draft-ietf-ipfix-mediation-protocol-02, Work
in Progress, July 2012.
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[IPFIX-IANA]
http://www.iana.org/assignments/ipfix/ipfix.xml
[PEN-IANA]
http://www.iana.org/assignments/enterprise-numbers
[IPFIX-XML-SCHEMA]
http://www.iana.org/assignments/xml-
registry/schema/ipfix.xsd
Authors' Addresses
Benoit Claise (Ed.)
Cisco Systems
De Kleetlaan 6a b1
1831 Diegem
Belgium
Phone: +32 2 704 5622
EMail: bclaise@cisco.com
Brian Trammell (Ed.)
Swiss Federal Institute of Technology Zurich
Gloriastrasse 35
8092 Zurich
Switzerland
Phone: +41 44 632 70 13
EMail: trammell@tik.ee.ethz.ch
Contributors' Addresses
Juergen Quittek
NEC
Kurfuersten-Anlage 36
Heidelberg 69115
Germany
Phone: +49 6221 90511-15
EMail: quittek@nw.neclab.eu
URI: http://www.neclab.eu/
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Stewart Bryant
Cisco Systems, Inc.
250, Longwater Ave., Green Park
Reading RG2 6GB
United Kingdom
EMail: stbryant@cisco.com
Paul Aitken
Cisco Systems, Inc.
96 Commercial Quay
Edinburgh EH6 6LX
Scotland
Phone: +44 131 561 3616
EMail: paitken@cisco.com
Jeff Meyer
PayPal
2211 N. First St.
San Jose, CA 95131-2021
US
Phone: +1 408 976-9149
EMail: jemeyer@paypal.com
URI: http://www.paypal.com
Claise, Trammell Standards Track [Page 23]
