Network Working Group                                     B. Claise, Ed.
Internet Draft                                       Cisco Systems, Inc.
Obsoletes: 5102                                         B. Trammell, Ed.
Category: Standards Track                                     ETH Zurich
Expires: January 14, 2013                                  July 13, 2012


        Information Model for IP Flow Information eXport (IPFIX)
          draft-ietf-ipfix-information-model-rfc5102bis-03.txt


Abstract

This document provides an overview of the information model for the IP
Flow Information eXport (IPFIX) protocol, as defined in the IANA IPFIX
Information Element Registry. It 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 March 23, 2012.

Copyright Notice

   Copyright (c) 2012 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



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   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 . . . . . . . . . . . . . . . . . . . . . . . . .  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  . . . . . . .  8
   3.  Type Space . . . . . . . . . . . . . . . . . . . . . . . . . .  9
     3.1.  Abstract Data Types  . . . . . . . . . . . . . . . . . . .  9
       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 . . . . . . . . . . . . . . . . . . . . . . . 10
       3.1.7.  signed32 . . . . . . . . . . . . . . . . . . . . . . . 10
       3.1.8.  signed64 . . . . . . . . . . . . . . . . . . . . . . . 10
       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 . . . . . . . . . . . . . . . . . . . 11
       3.1.16.  dateTimeMilliseconds  . . . . . . . . . . . . . . . . 11
       3.1.17.  dateTimeMicroseconds  . . . . . . . . . . . . . . . . 11
       3.1.18.  dateTimeNanoseconds . . . . . . . . . . . . . . . . . 11
       3.1.19.  ipv4Address . . . . . . . . . . . . . . . . . . . . . 11
       3.1.20.  ipv6Address . . . . . . . . . . . . . . . . . . . . . 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
       3.2.5.  flags  . . . . . . . . . . . . . . . . . . . . . . . . 12
   4.  Information Element Identifiers  . . . . . . . . . . . . . . . 12
     4.1.  NetFlow version 9 compatible Information Element
           Identifiers  . . . . . . . . . . . . . . . . . . . . . . . 13



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   5.  Information Element Categories . . . . . . . . . . . . . . . . 15
     5.1.  Identifiers  . . . . . . . . . . . . . . . . . . . . . . . 16
     5.3.  Metering and Exporting Process Statistics  . . . . . . . . 17
     5.4.  IP Header Fields . . . . . . . . . . . . . . . . . . . . . 17
     5.5.  Transport Header Fields  . . . . . . . . . . . . . . . . . 18
     5.6.  Sub-IP Header Fields . . . . . . . . . . . . . . . . . . . 19
     5.7.  Derived Packet Properties  . . . . . . . . . . . . . . . . 19
     5.9.  Flow Timestamps  . . . . . . . . . . . . . . . . . . . . . 20
     5.10.  Per-Flow Counters . . . . . . . . . . . . . . . . . . . . 20
     5.11.  Miscellaneous Flow Properties . . . . . . . . . . . . . . 21
     5.12.  Padding . . . . . . . . . . . . . . . . . . . . . . . . . 22
   6.  Extending the Information Model  . . . . . . . . . . . . . . . 22
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 23
     7.1.  IPFIX Information Elements . . . . . . . . . . . . . . . . 23
     7.2.  MPLS Label Type Identifier . . . . . . . . . . . . . . . . 23
     7.3.  XML Namespace and Schema . . . . . . . . . . . . . . . . . 23
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 24
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 25
   10.  References  . . . . . . . . . . . . . . . . . . . . . . . . . 25
     10.1.  Normative References  . . . . . . . . . . . . . . . . . . 25
     10.2.  Informative References  . . . . . . . . . . . . . . . . . 25
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29



OPEN ISSUES:

   review the NetFlow V9-compatible Information Elements table in
   Section 4 to ensure that it includes V9 IEs recently made
   compatible/non-proprietary: 82, 83, 91, 98, 99. What about
   deltaFlowCount (3)? On second thought, consider removing these
   tables, they add nothing and ignore the last five years.

1.  Introduction

   The IP Flow Information eXport (IPFIX) protocol serves for
   transmitting information related to measured IP traffic over the
   Internet.  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 canonical reference for IPFIX Information Elements the IANA IPFIX
   Information Element registry [IPFIX-IANA]; the initial values for



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   this registry were provided by [RFC5102].

   This document complements the IPFIX protocol specification 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].  The IPFIX information model
   does not specify relationships between Information Elements, but also
   it does not specify a concrete encoding of Information Elements.
   Besides the encoding used by the IPFIX 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:

   - EDITOR'S NOTE: not sure if we need to this information
      Errata ID: 1307 (technical)
      Errata ID: 1492 (technical)
      Errata ID: 1736 (technical)
      Errata ID: 2879 (editorial)
      Errata ID: 2944, which updates 1737 (technical)
      Errata ID: 2945, which updates 1738 (technical)
      Errata ID: 2946, which updates 1739 (technical)
      Updated the reference to RFC5101bis
      Clarified the time-related IEs

   - Since this document is based on the IPFIX Draft Standard
   [RFC5101bis], all improvements have been taken into account. For
   example, the timestamps.- Instead of repeating every Information
   Elements from [RFC5102], a reference to the IPFIX IANA registry
   [IPFIX-IANA] is introduced. However the category in section 5 have
   been kept.- The appendix A and B have been removed- Introduced
   [IPFIX-IE-DOCTORS]


1.2. IPFIX Documents Overview



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   The IPFIX protocol provides network administrators with access to IP
   flow information.  The architecture for the export of measured IP
   flow information out of an IPFIX Exporting Process to a Collecting
   Process is defined in [RFC5470], per the requirements defined in
   [RFC3917].  The IPFIX specifications [RFC5101bis] document specifies
   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 flow 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 IPIFX Mediation Framework [RFC6183].

   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].

   [IPFIX-CONF] specifies a data model for configuring and monitoring
   IPFIX and PSAMP compliant devices using the NETCONF protocol, while
   the [RFC5815bis] 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]. For specifying these Information Elements, a template is used
   that is described below.

   All Information Elements specified for the IPFIX protocol MUST have
   the following properties defined:

   name - A unique and meaningful name for the Information Element.



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   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 a length constraints
      (fixed length, minimum and/or maximum length) MUST note these
      constraints in their description.

   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 does however
      encompass most basic types used in modern programming languages,
      as well as some derived types (such as ipv4Address) that are
      common to this domain and useful to distinguish.

   status - The status of the specification of this Information Element.
      Allowed values are 'current', 'deprecated', and 'obsolete'. All
      newly-defined Information Elements have 'current' status. The
      process for moving Information Elements to the 'deprecated' or
      'obsolete' 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 codes.
      They are defined at http://www.iana.org/assignments/enterprise-
      numbers.

   All Information Elements specified for the IPFIX protocol either in
   this document or by any future extension MAY have the following



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   properties defined:

   dataTypeSemantics - The integral types may be 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.

   reference - Identifies additional specifications that more precisely
      define this item or provide additional context for its use.

   Information Elements replacing an enterprise-specific Information
   Element used for experimental or pre-standardization purposes SHOULD
   define the following property, as outlined in Section 4.9 of [IPFIX-
   IE-DOCTORS].

   enterpriseSpecificReference - The enterpriseId and elementId of the
      enterprise-specific Information Element(s) replaced by this
      Information Element.

   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.

   For Information Elements of the string or octetArray data types which
   have size limits (minimum and/or maximum size, or fixed length), the
   limits MUST be defined within the description of the Information
   Element.

2.2.  Scope of Information Elements

   By default, most Information Elements have a scope specified in their
   definitions.



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   o  The Information Elements listed in Sections 5.2 and 5.3, and
      similar Information Elements in [IPFIX-IANA], have a default of "a
      specific Metering Process" or of "a specific Exporting Process",
      respectively.

   o  The Information Elements listed in Sections 5.4-5.11, and similar
      Information Elements in [IPFIX-IANA], have a scope of "a specific
      Flow".

   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
      registry.   Enterprise-specific Information Elements SHOULD be
      prefixed with a vendor name.

   o  Names of Information Elements MUST start with non-capitalized
      letters.

   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



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      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.  Note that further abstract data types may
   be specified by future extensions of the IPFIX information model.

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




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   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.

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 string of 6 octets.

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 character encoding set
   [ISO.10646-1.1993].  Unicode allows for ASCII [ISO.646.1991] and many
   other international character sets to be used.




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3.1.15.  dateTimeSeconds

   The data type dateTimeSeconds is an unsigned 32-bit integer
   representing the number of seconds since the UNIX epoch, 1 January
   1970 at 00:00 UTC, as defined in [POSIX.1].

3.1.16.  dateTimeMilliseconds

   The data type dateTimeMilliseconds is an unsigned 64-bit integer
   containing the number of milliseconds since the UNIX epoch, 1 January
   1970 at 00:00 UTC, as defined in [POSIX.1].

3.1.17.  dateTimeMicroseconds

   The type "dateTimeMicroseconds" represents a time value with
   microsecond precision according to the NTP Timestamp format as
   defined in section 6 of [RFC5905].

3.1.18.  dateTimeNanoseconds

   The type "dateTimeNanoseconds" represents a time value with
   nanosecond precision according to the NTP Timestamp format as defined
   in section 6 of [RFC5905].

3.1.19.  ipv4Address

   The type "ipv4Address" represents a value of an IPv4 address.

3.1.20.  ipv6Address

   The type "ipv6Address" represents a value of an IPv6 address.

3.2.  Data Type Semantics

   This section describes the set of valid data type semantics of the
   IPFIX information model. A registry of data type semantics is
   established in [RFC5610]; the restrictions specified in section 3.10
   of that document are followed here. Note that further data type
   semantics may be specified by future extensions of the IPFIX
   information model. These semantics apply only to numeric types, as
   noted in the description of each semantic below.

3.2.1.  quantity

   A numeric (integral or floating point) value representing a measured
   value pertaining to the record. This is distinguished from counters
   that represent an ongoing measured value whose "odometer" reading is
   captured as part of a given record. This is the default semantic type



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   of all numeric data types.

3.2.2.  totalCounter

   An numeric 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 numeric 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 its value is exported.

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.

4.  Information Element Identifiers

   All Information Elements defined in the IANA IPFIX Information
   Element registry [IPFIX-IANA] have their identifiers assigned by
   IANA.




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   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]; Information Element identifiers in this range MUST NOT be
   assigned unless the Information Element is compatible with the
   NetFlow version 9 protocol. Such Information Elements may ONLY be
   requested by a NetFlow v9 expert, to be designated by the IESG.

   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 MUST be registered as SMI network management
   private enterprise code numbers with IANA.  The registry can be found
   at http://www.iana.org/assignments/enterprise-numbers.

4.1.  NetFlow version 9 compatible Information Element Identifiers

   The following list gives an overview of the Information Element
   identifiers that are compatible with field types used by NetFlow
   version 9 [RFC3954].




















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   +----+----------------------------+-------+-------------------------+
   | ID | Name                       |    ID | Name                    |
   +----+----------------------------+-------+-------------------------+
   |  1 | octetDeltaCount            |    43 | RESERVED                |
   |  2 | packetDeltaCount           |    44 | sourceIPv4Prefix        |
   |  3 | RESERVED                   |    45 | destinationIPv4Prefix   |
   |  4 | protocolIdentifier         |    46 | mplsTopLabelType        |
   |  5 | ipClassOfService           |    47 | mplsTopLabelIPv4Address |
   |  6 | tcpControlBits             | 48-51 | RESERVED                |
   |  7 | sourceTransportPort        |    52 | minimumTTL              |
   |  8 | sourceIPv4Address          |    53 | maximumTTL              |
   |  9 | sourceIPv4PrefixLength     |    54 | fragmentIdentification  |
   | 10 | ingressInterface           |    55 | postIpClassOfService    |
   | 11 | destinationTransportPort   |    56 | sourceMacAddress        |
   | 12 | destinationIPv4Address     |    57 |postDestinationMacAddress|
   | 13 | destinationIPv4PrefixLength|    58 | vlanId                  |
   | 14 | egressInterface            |    59 | postVlanId              |
   | 15 | ipNextHopIPv4Address       |    60 | ipVersion               |
   | 16 | bgpSourceAsNumber          |    61 | flowDirection           |
   | 17 | bgpDestinationAsNumber     |    62 | ipNextHopIPv6Address    |
   | 18 | bgpNexthopIPv4Address      |    63 | bgpNexthopIPv6Address   |
   | 19 | postMCastPacketDeltaCount  |    64 | ipv6ExtensionHeaders    |
   | 20 | postMCastOctetDeltaCount   | 65-69 | RESERVED                |
   | 21 | flowEndSysUpTime           |    70 | mplsTopLabelStackSection|
   | 22 | flowStartSysUpTime         |    71 | mplsLabelStackSection2  |
   | 23 | postOctetDeltaCount        |    72 | mplsLabelStackSection3  |
   | 24 | postPacketDeltaCount       |    73 | mplsLabelStackSection4  |
   | 25 | minimumIpTotalLength       |    74 | mplsLabelStackSection5  |
   | 26 | maximumIpTotalLength       |    75 | mplsLabelStackSection6  |
   | 27 | sourceIPv6Address          |    76 | mplsLabelStackSection7  |
   | 28 | destinationIPv6Address     |    77 | mplsLabelStackSection8  |
   | 29 | sourceIPv6PrefixLength     |    78 | mplsLabelStackSection9  |
   | 30 | destinationIPv6PrefixLength|    79 | mplsLabelStackSection10 |
   | 31 | flowLabelIPv6              |    80 | destinationMacAddress   |
   | 32 | icmpTypeCodeIPv4           |    81 | postSourceMacAddress    |
   | 33 | igmpType                   | 82-84 | RESERVED                |
   | 34 | RESERVED                   |    85 | octetTotalCount         |
   | 35 | RESERVED                   |    86 | packetTotalCount        |
   | 36 | flowActiveTimeout          |    87 | RESERVED                |
   | 37 | flowIdleTimeout            |    88 | fragmentOffset          |
   | 38 | RESERVED                   |    89 | RESERVED                |
   | 39 | RESERVED                   |    90 |mplsVpnRouteDistinguisher|
   | 40 | exportedOctetTotalCount    |91-127 | RESERVED                |
   | 41 | exportedMessageTotalCount  |       |                         |
   | 42 |exportedFlowRecordTotalCount|       |                         |
   +----+----------------------------+-------+-------------------------+





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5.  Information Element Categories

   This section describes the Information Element category for the IPFIX
   information model at the time that [RFC5102] was published. Since
   this category field is not part of the IANA process for assigning new
   Information Element (even though it has been reused, for example, in
   [RFC5103]), the newest Information Elements in IANA [IPFIX-IANA]
   don't have this classification. The elements are grouped into 12
   groups according to their semantics and their applicability:

   1.   Identifiers
   2.   Metering and Exporting Process Configuration
   3.   Metering and Exporting Process Statistics
   4.   IP Header Fields
   5.   Transport Header Fields
   6.   Sub-IP Header Fields
   7.   Derived Packet Properties
   8.   Min/Max Flow Properties
   9.   Flow Timestamps
   10.  Per-Flow Counters
   11.  Miscellaneous Flow Properties
   12.  Padding

   The Information Elements that are derived from fields of packets or
   from packet treatment, such as the Information Elements in groups
   4-7, can typically serve as Flow Keys used for mapping packets to
   Flows.

   If they do not serve as Flow Keys, their value may change from packet
   to packet within a single Flow.  For Information Elements with values
   that are derived from fields of packets or from packet treatment and
   for which the value may change from packet to packet within a single
   Flow, the IPFIX information model defines that their value is
   determined by the first packet observed for the corresponding Flow,
   unless the description of the Information Element explicitly
   specifies a 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,
   such as the Information Elements in groups 8-11, need to be updated.

   Information Elements with a name having the "post" prefix, for
   example, "postIpClassOfService", do not report properties that were
   actually observed at the Observation Point, but 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.



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Internet-Draft          IPFIX Information Model            July 13, 2012


5.1.  Identifiers

   Information Elements grouped in the table below are identifying
   components of the IPFIX architecture, of an IPFIX Device, or of the
   IPFIX protocol.  All of them have an integral abstract data type and
   data type semantics "identifier" as described in Section 3.2.4.

   Typically, some of them are used for limiting scopes of other
   Information Elements.  However, other Information Elements MAY be
   used for limiting scopes.  Note also that all Information Elements
   listed below MAY be used for other purposes than limiting scopes.

   +-----+---------------------------+-----+---------------------------+
   |  ID | Name                      |  ID | Name                      |
   +-----+---------------------------+-----+---------------------------+
   | 141 | lineCardId                | 148 | flowId                    |
   | 142 | portId                    | 145 | templateId                |
   |  10 | ingressInterface          | 149 | observationDomainId       |
   |  14 | egressInterface           | 138 | observationPointId        |
   | 143 | meteringProcessId         | 137 | commonPropertiesId        |
   | 144 | exportingProcessId        |     |                           |
   +-----+---------------------------+-----+---------------------------+

   See [