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Network Working Group                                     B. Claise, Ed.Request for Comments: 5101                           Cisco Systems, Inc.Category: Standards Track                                   January 2008Specification of the IP Flow Information Export (IPFIX) Protocolfor the Exchange of IP Traffic Flow InformationStatus of This Memo   This document specifies an Internet standards track protocol for the   Internet community, and requests discussion and suggestions for   improvements.  Please refer to the current edition of the "Internet   Official Protocol Standards" (STD 1) for the standardization state   and status of this protocol.  Distribution of this memo is unlimited.Abstract   This document specifies the IP Flow Information Export (IPFIX)   protocol that serves for transmitting IP Traffic Flow information   over the network.  In order to transmit IP Traffic Flow information   from an Exporting Process to an information Collecting Process, a   common representation of flow data and a standard means of   communicating them is required.  This document describes how the   IPFIX Data and Template Records are carried over a number of   transport protocols from an IPFIX Exporting Process to an IPFIX   Collecting Process.Table of Contents1. Introduction ....................................................31.1. IPFIX Documents Overview ...................................42. Terminology .....................................................42.1. Terminology Summary Table ..................................93. IPFIX Message Format ...........................................103.1. Message Header Format .....................................113.2. Field Specifier Format ....................................133.3. Set and Set Header Format .................................143.3.1. Set Format .........................................143.3.2. Set Header Format ..................................153.4. Record Format .............................................163.4.1. Template Record Format .............................163.4.2. Options Template Record Format .....................183.4.2.1. Scope .....................................193.4.2.2. Options Template Record Format ............203.4.3. Data Record Format .................................224. Specific Reporting Requirements ................................234.1. The Metering Process Statistics Option Template ...........23Claise, et al.              Standards Track                     [Page 1]

RFC 5101              IPFIX Protocol Specification          January 2008      4.2. The Metering Process Reliability Statistics Option           Template ..................................................24      4.3. The Exporting Process Reliability Statistics           Option Template ...........................................254.4. The Flow Keys Option Template .............................265. IPFIX Message Header "Export Time" and Flow Record Time ........276. Linkage with the Information Model .............................286.1. Encoding of IPFIX Data Types ..............................286.1.1. Integral Data Types ................................286.1.2. Address Types ......................................286.1.3. float32 ............................................286.1.4. float64 ............................................286.1.5. boolean ............................................286.1.6. string and octetarray ..............................286.1.7. dateTimeSeconds ....................................296.1.8. dateTimeMilliseconds ...............................296.1.9. dateTimeMicroseconds ...............................29           6.1.10.dateTimeNanoseconds.................................296.2. Reduced Size Encoding of Integer and Float Types ..........297. Variable-Length Information Element ............................308. Template Management ............................................319. The Collecting Process's Side ..................................3410. Transport Protocol ............................................3610.1. Transport Compliance and Transport Usage .................3610.2. SCTP .....................................................3710.2.1. Congestion Avoidance ..............................3710.2.2. Reliability .......................................3710.2.3. MTU ...............................................3710.2.4. Exporting Process .................................3810.2.4.1. Association Establishment ................3810.2.4.2. Association Shutdown .....................3810.2.4.3. Stream ...................................3810.2.4.4. Template Management ......................3910.2.5. Collecting Process ................................3910.2.6. Failover ..........................................3910.3. UDP ......................................................3910.3.1. Congestion Avoidance ..............................3910.3.2. Reliability .......................................4010.3.3. MTU ...............................................4010.3.4. Port Numbers ......................................4010.3.5. Exporting Process .................................4010.3.6. Template Management ...............................4010.3.7. Collecting Process ................................4110.3.8. Failover ..........................................4210.4. TCP ......................................................4210.4.1. Connection Management .............................4210.4.1.1. Connection Establishment .................4210.4.1.2. Graceful Connection Release ..............43Claise, et al.              Standards Track                     [Page 2]

RFC 5101              IPFIX Protocol Specification          January 200810.4.1.3. Restarting Interrupted Connections .......4310.4.1.4. Failover .................................4310.4.2. Data Transmission .................................4310.4.2.1. IPFIX Message Encoding ...................4310.4.2.2. Template Management ......................4410.4.2.3. Congestion Handling and Reliability ......4410.4.3. Collecting Process ................................4511. Security Considerations .......................................4611.1. Applicability of TLS and DTLS ............................4711.2. Usage ....................................................4811.3. Authentication ...........................................4811.4. Protection against DoS Attacks ...........................4811.5. When DTLS or TLS Is Not an Option ........................5011.6. Logging an IPFIX Attack ..................................5011.7. Securing the Collector ...................................5112. IANA Considerations ...........................................51Appendix A. IPFIX Encoding Examples ...............................52A.1. Message Header Example.....................................52A.2. Template Set Examples......................................53           A.2.1. Template Set Using IETF-Specified Information                  Elements ...........................................53           A.2.2. Template Set Using Enterprise-Specific Information                  Elements ...........................................53A.3. Data Set Example ..........................................55A.4. Options Template Set Examples .............................56           A.4.1. Options Template Set Using IETF-Specified                  Information Elements ...............................56           A.4.2. Options Template Set Using Enterprise-Specific                  Information Elements ...............................56           A.4.3. Options Template Set Using an Enterprise-Specific                  Scope ..............................................57A.4.4. Data Set Using an Enterprise-Specific Scope ........58A.5. Variable-Length Information Element Examples ..............59           A.5.1. Example of Variable-Length Information Element                  with Length Inferior to 255 Octets .................59           A.5.2. Example of Variable-Length Information Element                  with Length 255 to 65535 Octets ....................59   References ........................................................59      Normative References ...........................................59      Informative References .........................................60   Acknowledgments ...................................................611.  Introduction   A data network with IP traffic primarily consists of IP flows passing   through the network elements.  It is often interesting, useful, or   even required to have access to information about these flows that   pass through the network elements for administrative or otherClaise, et al.              Standards Track                     [Page 3]

RFC 5101              IPFIX Protocol Specification          January 2008   purposes.  The IPFIX Collecting Process should be able to receive the   flow information passing through multiple network elements within the   data network.  This requires uniformity in the method of representing   the flow information and the means of communicating the flows from   the network elements to the collection point.  This document   specifies the protocol to achieve these aforementioned requirements.   This document specifies in detail the representation of different   flows, the additional data required for flow interpretation, packet   format, transport mechanisms used, security concerns, etc.1.1.  IPFIX Documents Overview   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 [IPFIX-ARCH], per the requirements defined in   [RFC3917].  This document specifies how IPFIX data records and   templates are carried via a number of transport protocols from IPFIX   Exporting Processes to IPFIX Collecting Processes.  IPFIX has a   formal description of IPFIX Information Elements, their name, type   and additional semantic information, as specified in [RFC5102].   Finally, [IPFIX-AS] 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.  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 inRFC 2119 [RFC2119].   The definitions of the basic terms like IP Traffic Flow, Exporting   Process, Collecting Process, Observation Points, etc.  are   semantically identical to those found in the IPFIX requirements   document [RFC3917].  Some of the terms have been expanded for more   clarity when defining the protocol.  Additional terms required for   the protocol have also been defined.  Definitions in this document   and in [IPFIX-ARCH] are equivalent, except that definitions that are   only relevant to the IPFIX protocol only appear here.   The terminology summary table inSection 2.1 gives a quick overview   of the relationships between some of the different terms defined.Claise, et al.              Standards Track                     [Page 4]

RFC 5101              IPFIX Protocol Specification          January 2008   Observation Point      An Observation Point is a location in the network where IP packets      can be observed.  Examples include: a line to which a probe is      attached, a shared medium, such as an Ethernet-based LAN, a single      port of a router, or a set of interfaces (physical or logical) of      a router.      Note that every Observation Point is associated with an      Observation Domain (defined below), and that one Observation Point      may be a superset of several other Observation Points.  For      example, one Observation Point can be an entire line card.  That      would be the superset of the individual Observation Points at the      line card's interfaces.   Observation Domain      An Observation Domain is the largest set of Observation Points for      which Flow information can be aggregated by a Metering Process.      For example, a router line card may be an Observation Domain if it      is composed of several interfaces, each of which is an Observation      Point.  In the IPFIX Message it generates, the Observation Domain      includes its Observation Domain ID, which is unique per Exporting      Process.  That way, the Collecting Process can identify the      specific Observation Domain from the Exporter that sends the IPFIX      Messages.  Every Observation Point is associated with an      Observation Domain.  It is RECOMMENDED that Observation Domain IDs      also be unique per IPFIX Device.   IP Traffic Flow or Flow      There are several definitions of the term 'flow' being used by the      Internet community.  Within the context of IPFIX we use the      following definition:      A Flow is defined as a set of IP packets passing an Observation      Point in the network during a certain time interval.  All packets      belonging to a particular Flow have a set of common properties.      Each property is defined as the result of applying a function to      the values of:         1. one or more packet header fields (e.g., destination IP            address), transport header fields (e.g., destination port            number), or application header fields (e.g., RTP header            fields [RFC3550]).         2. one or more characteristics of the packet itself (e.g.,            number of MPLS labels, etc...).Claise, et al.              Standards Track                     [Page 5]

RFC 5101              IPFIX Protocol Specification          January 2008         3. one or more of fields derived from packet treatment (e.g.,            next hop IP address, the output interface, etc...).      A packet is defined as belonging to a Flow if it completely      satisfies all the defined properties of the Flow.      This definition covers the range from a Flow containing all      packets observed at a network interface to a Flow consisting of      just a single packet between two applications.  It includes      packets selected by a sampling mechanism.   Flow Key      Each of the fields that:      1.  belong to the packet header (e.g., destination IP address),      2.  are a property of the packet itself (e.g., packet length),      3.  are derived from packet treatment (e.g., Autonomous System          (AS) number),      and that are used to define a Flow are termed Flow Keys.   Flow Record      A Flow Record contains information about a specific Flow that was      observed at an Observation Point.  A Flow Record contains measured      properties of the Flow (e.g., the total number of bytes for all      the Flow's packets) and usually characteristic properties of the      Flow (e.g., source IP address).   Metering Process      The Metering Process generates Flow Records.  Inputs to the      process are packet headers and characteristics observed at an      Observation Point, and packet treatment at the Observation Point      (for example, the selected output interface).      The Metering Process consists of a set of functions that includes      packet header capturing, timestamping, sampling, classifying, and      maintaining Flow Records.      The maintenance of Flow Records may include creating new records,      updating existing ones, computing Flow statistics, deriving      further Flow properties, detecting Flow expiration, passing Flow      Records to the Exporting Process, and deleting Flow Records.Claise, et al.              Standards Track                     [Page 6]

RFC 5101              IPFIX Protocol Specification          January 2008   Exporting Process      The Exporting Process sends Flow Records to one or more Collecting      Processes.  The Flow Records are generated by one or more Metering      Processes.   Exporter      A device that hosts one or more Exporting Processes is termed an      Exporter.   IPFIX Device      An IPFIX Device hosts at least one Exporting Process.  It may host      further Exporting Processes and arbitrary numbers of Observation      Points and Metering Processes.   Collecting Process      A Collecting Process receives Flow Records from one or more      Exporting Processes.  The Collecting Process might process or      store received Flow Records, but such actions are out of scope for      this document.   Collector      A device that hosts one or more Collecting Processes is termed a      Collector.   Template      A Template is an ordered sequence of <type, length> pairs used to      completely specify the structure and semantics of a particular set      of information that needs to be communicated from an IPFIX Device      to a Collector.  Each Template is uniquely identifiable by means      of a Template ID.   IPFIX Message      An IPFIX Message is a message originating at the Exporting Process      that carries the IPFIX records of this Exporting Process and whose      destination is a Collecting Process.  An IPFIX Message is      encapsulated at the transport layer.Claise, et al.              Standards Track                     [Page 7]

RFC 5101              IPFIX Protocol Specification          January 2008   Message Header      The Message Header is the first part of an IPFIX Message, which      provides basic information about the message, such as the IPFIX      version, length of the message, message sequence number, etc.   Template Record      A Template Record defines the structure and interpretation of      fields in a Data Record.   Data Record      A Data Record is a record that contains values of the parameters      corresponding to a Template Record.   Options Template Record      An Options Template Record is a Template Record that defines the      structure and interpretation of fields in a Data Record, including      defining how to scope the applicability of the Data Record.   Set      Set is a generic term for a collection of records that have a      similar structure.  In an IPFIX Message, one or more Sets follow      the Message Header.      There are three different types of Sets: Template Set, Options      Template Set, and Data Set.   Template Set      A Template Set is a collection of one or more Template Records      that have been grouped together in an IPFIX Message.   Options Template Set      An Options Template Set is a collection of one or more Options      Template Records that have been grouped together in an IPFIX      Message.   Data Set      A Data Set is one or more Data Records, of the same type, that are      grouped together in an IPFIX Message.  Each Data Record is      previously defined by a Template Record or an Options Template      Record.Claise, et al.              Standards Track                     [Page 8]

RFC 5101              IPFIX Protocol Specification          January 2008   Information Element      An Information Element is a protocol and encoding-independent      description of an attribute that may appear in an IPFIX Record.      The IPFIX information model [RFC5102] defines the base set of      Information Elements for IPFIX.  The type associated with an      Information Element indicates constraints on what it may contain      and also determines the valid encoding mechanisms for use in      IPFIX.   Transport Session      In Stream Control Transmission Protocol (SCTP), the transport      session is known as the SCTP association, which is uniquely      identified by the SCTP endpoints [RFC4960]; in TCP, the transport      session is known as the TCP connection, which is uniquely      identified by the combination of IP addresses and TCP ports used.      In UDP, the transport session is known as the UDP session, which      is uniquely identified by the combination of IP addresses and UDP      ports used.2.1.  Terminology Summary Table   +------------------+---------------------------------------------+   |                  |                 contents                    |   |                  +--------------------+------------------------+   |       Set        |      Template      |         record         |   +------------------+--------------------+------------------------+   |     Data Set     |          /         |     Data Record(s)     |   +------------------+--------------------+------------------------+   |   Template Set   | Template Record(s) |           /            |   +------------------+--------------------+------------------------+   | Options Template | Options Template   |           /            |   |       Set        | Record(s)          |                        |   +------------------+--------------------+------------------------+   Figure A: Terminology Summary Table   A Data Set is composed of Data Record(s).  No Template Record is   included.  A Template Record or an Options Template Record defines   the Data Record.   A Template Set contains only Template Record(s).   An Options Template Set contains only Options Template Record(s).Claise, et al.              Standards Track                     [Page 9]

RFC 5101              IPFIX Protocol Specification          January 20083.  IPFIX Message Format   An IPFIX Message consists of a Message Header, followed by one or   more Sets.  The Sets can be any of the possible three types: Data   Set, Template Set, or Options Template Set.   The format of the IPFIX Message is shown in Figure B.   +----------------------------------------------------+   | Message Header                                     |   +----------------------------------------------------+   | Set                                                |   +----------------------------------------------------+   | Set                                                |   +----------------------------------------------------+     ...   +----------------------------------------------------+   | Set                                                |   +----------------------------------------------------+   Figure B: IPFIX Message Format   The Exporter MUST code all binary integers of the Message Header and   the different Sets in network-byte order (also known as the   big-endian byte ordering).   Following are some examples of IPFIX Messages:   1. An IPFIX Message consisting of interleaved Template, Data, and      Options Template Sets -- A newly created Template is exported as      soon as possible.  So, if there is already an IPFIX Message with a      Data Set that is being prepared for export, the Template and      Option Template Sets are interleaved with this information,      subject to availability of space.   +--------+--------------------------------------------------------+   |        | +----------+ +---------+     +-----------+ +---------+ |   |Message | | Template | | Data    |     | Options   | | Data    | |   | Header | | Set      | | Set     | ... | Template  | | Set     | |   |        | |          | |         |     | Set       | |         | |   |        | +----------+ +---------+     +-----------+ +---------+ |   +--------+--------------------------------------------------------+   Figure C: IPFIX Message, Example 1Claise, et al.              Standards Track                    [Page 10]

RFC 5101              IPFIX Protocol Specification          January 2008   2. An IPFIX Message consisting entirely of Data Sets -- After the      appropriate Template Records have been defined and transmitted to      the Collecting Process, the majority of IPFIX Messages consist      solely of Data Sets.   +--------+----------------------------------------------+   |        | +---------+     +---------+      +---------+ |   |Message | | Data    |     | Data    |      | Data    | |   | Header | | Set     | ... | Set     | ...  | Set     | |   |        | +---------+     +---------+      +---------+ |   +--------+----------------------------------------------+   Figure D: IPFIX Message, Example 2   3. An IPFIX Message consisting entirely of Template and Options      Template Sets.   +--------+-------------------------------------------------+   |        | +----------+     +----------+      +----------+ |   |Message | | Template |     | Template |      | Options  | |   | Header | | Set      | ... | Set      | ...  | Template | |   |        | |          |     |          |      | Set      | |   |        | +----------+     +----------+      +----------+ |   +--------+-------------------------------------------------+   Figure E: IPFIX Message, Example 33.1.  Message Header Format   The format of the IPFIX Message Header is shown in Figure F.    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 F: IPFIX Message Header FormatClaise, et al.              Standards Track                    [Page 11]

RFC 5101              IPFIX Protocol Specification          January 2008   Message Header Field Descriptions:   Version      Version of Flow Record format exported in this message.  The value      of this field is 0x000a for the current version, incrementing by      one the version used in the NetFlow services export version 9      [RFC3954].   Length      Total length of the IPFIX Message, measured in octets, including      Message Header and Set(s).   Export Time      Time, in seconds, since 0000 UTC Jan 1, 1970, at which the IPFIX      Message Header leaves the Exporter.   Sequence Number      Incremental sequence counter modulo 2^32 of all IPFIX Data Records      sent on this PR-SCTP stream from the current Observation Domain by      the Exporting Process.  Check the specific meaning of this field      in the subsections ofSection 10 when UDP or TCP is selected as      the transport protocol.  This value SHOULD be used by the      Collecting Process to identify whether any IPFIX Data Records have      been missed.  Template and Options Template Records do not      increase the Sequence Number.   Observation Domain ID      A 32-bit identifier of the Observation Domain that is locally      unique to the Exporting Process.  The Exporting Process uses the      Observation Domain ID to uniquely identify to the Collecting      Process the Observation Domain that metered the Flows.  It is      RECOMMENDED that this identifier also be unique per IPFIX Device.      Collecting Processes SHOULD use the Transport Session and the      Observation Domain ID field to separate different export streams      originating from the same Exporting Process.  The Observation      Domain ID SHOULD be 0 when no specific Observation Domain ID is      relevant for the entire IPFIX Message, for example, when exporting      the Exporting Process Statistics, or in case of a hierarchy of      Collectors when aggregated Data Records are exported.Claise, et al.              Standards Track                    [Page 12]

RFC 5101              IPFIX Protocol Specification          January 20083.2.  Field Specifier Format   Vendors need the ability to define proprietary Information Elements,   because, for example, they are delivering a pre-standards product, or   the Information Element is, in some way, commercially sensitive.   This section describes the Field Specifier format for both   IETF-specified Information Elements [RFC5102] and enterprise-specific   Information Elements.   The Information Elements are identified by the Information Element   identifier.  When the Enterprise bit is set to 0, the corresponding   Information Element identifier will report an IETF-specified   Information Element, and the Enterprise Number MUST NOT be present.   When the Enterprise bit is set to 1, the corresponding Information   Element identifier will report an enterprise-specific Information   Element; the Enterprise Number MUST be present.  An example of this   is shown in Section A.4.2.   The Field Specifier format is shown in Figure G.   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   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |E|  Information Element ident. |        Field Length           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                      Enterprise Number                        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure G: Field Specifier Format   Where:   E      Enterprise bit.  This is the first bit of the Field Specifier.  If      this bit is zero, the Information Element Identifier identifies an      IETF-specified Information Element, and the four-octet Enterprise      Number field MUST NOT be present.  If this bit is one, the      Information Element identifier identifies an enterprise-specific      Information Element, and the Enterprise Number filed MUST be      present.   Information Element identifier      A numeric value that represents the type of Information Element.      Refer to [RFC5102].Claise, et al.              Standards Track                    [Page 13]

RFC 5101              IPFIX Protocol Specification          January 2008   Field Length      The length of the corresponding encoded Information Element, in      octets.  Refer to [RFC5102].  The field length may be smaller than      the definition in [RFC5102] if the reduced size encoding is used      (seeSection 6.2).  The value 65535 is reserved for variable-      length Information Elements (seeSection 7).   Enterprise Number      IANA enterprise number [PEN] of the authority defining the      Information Element identifier in this Template Record.3.3.  Set and Set Header Format   A Set is a generic term for a collection of records that have a   similar structure.  There are three different types of Sets: Template   Sets, Options Template Sets, and Data Sets.  Each of these Sets   consists of a Set Header and one or more records.  The Set Format and   the Set Header Format are defined in the following sections.3.3.1.  Set Format   A Set has the format shown in Figure H.  The record types can be   either Template Records, Options Template Records, or Data Records.   The record types MUST NOT be mixed within a Set.   +--------------------------------------------------+   | Set Header                                       |   +--------------------------------------------------+   | record                                           |   +--------------------------------------------------+   | record                                           |   +--------------------------------------------------+    ...   +--------------------------------------------------+   | record                                           |   +--------------------------------------------------+   | Padding (opt.)                                   |   +--------------------------------------------------+   Figure H: Set Format   The Set Field Definitions are as follows:   Set Header      The Set Header Format is defined inSection 3.3.2.Claise, et al.              Standards Track                    [Page 14]

RFC 5101              IPFIX Protocol Specification          January 2008   Record      One of the record Formats: Template Record, Options Template      Record, or Data Record Format.   Padding      The Exporting Process MAY insert some padding octets, so that the      subsequent Set starts at an aligned boundary.  For security      reasons, the padding octet(s) MUST be composed of zero (0) valued      octets.  The padding length MUST be shorter than any allowable      record in this Set.  If padding of the IPFIX Message is desired in      combination with very short records, then the padding Information      Element 'paddingOctets' [RFC5102] can be used for padding records      such that their length is increased to a multiple of 4 or 8      octets.  Because Template Sets are always 4-octet aligned by      definition, padding is only needed in case of other alignments      e.g., on 8-octet boundaries.3.3.2.  Set Header Format   Every Set contains a common header.  This header is defined in Figure   I.    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 I: Set Header Format   The Set Header Field Definitions are as follows:   Set ID      Set ID value identifies the Set.  A value of 2 is reserved for the      Template Set.  A value of 3 is reserved for the Option Template      Set.  All other values from 4 to 255 are reserved for future use.      Values above 255 are used for Data Sets.  The Set ID values of 0      and 1 are not used for historical reasons [RFC3954].   Length      Total length of the Set, in octets, including the Set Header, all      records, and the optional padding.  Because an individual Set MAY      contain multiple records, the Length value MUST be used to      determine the position of the next Set.Claise, et al.              Standards Track                    [Page 15]

RFC 5101              IPFIX Protocol Specification          January 20083.4.   Record Format   IPFIX defines three record formats, defined in the next sections: the   Template Record Format, the Options Template Record Format, and the   Data Record Format.3.4.1.  Template Record Format   One of the essential elements in the IPFIX record format is the   Template Record.  Templates greatly enhance the flexibility of the   record format because they allow the Collecting Process to process   IPFIX Messages without necessarily knowing the interpretation of all   Data Records.  A Template Record contains any combination of   IANA-assigned and/or enterprise-specific Information Elements   identifiers.   The format of the Template Record is shown in Figure J.  It consists   of a Template Record Header and one or more Field Specifiers.  The   definition of the Field Specifiers is given in Figure G above.   +--------------------------------------------------+   | Template Record Header                           |   +--------------------------------------------------+   | Field Specifier                                  |   +--------------------------------------------------+   | Field Specifier                                  |   +--------------------------------------------------+    ...   +--------------------------------------------------+   | Field Specifier                                  |   +--------------------------------------------------+   Figure J: Template Record Format   The format of the Template Record Header is shown in Figure K.    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   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |      Template ID (> 255)      |         Field Count           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure K: Template Record Header FormatClaise, et al.              Standards Track                    [Page 16]

RFC 5101              IPFIX Protocol Specification          January 2008   The Template Record Header Field Definitions are as follows:   Template ID      Each of the newly generated Template Records is given a unique      Template ID.  This uniqueness is local to the Transport Session      and Observation Domain that generated the Template ID.  Template      IDs 0-255 are reserved for Template Sets, Options Template Sets,      and other reserved Sets yet to be created.  Template IDs of Data      Sets are numbered from 256 to 65535.  There are no constraints      regarding the order of the Template ID allocation.   Field Count      Number of fields in this Template Record.   The example in Figure L shows a Template Set with mixed standard and   enterprise-specific Information Elements.  It consists of a Set   Header, a Template Header, and several Field Specifiers.Claise, et al.              Standards Track                    [Page 17]

RFC 5101              IPFIX Protocol Specification          January 2008    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 = 2           |          Length               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |      Template ID = 256        |         Field Count = N       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |1| Information Element id. 1.1 |        Field Length 1.1       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                    Enterprise Number  1.1                     |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0| Information Element id. 1.2 |        Field Length 1.2       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |             ...               |              ...              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |1| Information Element id. 1.N |        Field Length 1.N       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                    Enterprise Number  1.N                     |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |      Template ID = 257        |         Field Count = M       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0| Information Element id. 2.1 |        Field Length 2.1       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |1| Information Element id. 2.2 |        Field Length 2.2       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                    Enterprise Number  2.2                     |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |             ...               |              ...              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |1| Information Element id. 2.M |        Field Length 2.M       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                    Enterprise Number  2.M                     |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          Padding (opt)                        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure L: Template Set Example   Information Element Identifiers 1.2 and 2.1 are defined by the IETF   (Enterprise bit = 0) and, therefore, do not need an Enterprise Number   to identify them.3.4.2.  Options Template Record Format   Thanks to the notion of scope, The Options Template Record gives the   Exporter the ability to provide additional information to the   Collector that would not be possible with Flow Records alone.Claise, et al.              Standards Track                    [Page 18]

RFC 5101              IPFIX Protocol Specification          January 2008   One Options Template Record example is the "Flow Keys", which reports   the Flow Keys for a Template, which is defined as the scope.  Another   example is the "Template configuration", which reports the   configuration sampling parameter(s) for the Template, which is   defined as the scope.3.4.2.1.  Scope   The scope, which is only available in the Options Template Set, gives   the context of the reported Information Elements in the Data Records.   Note that the IPFIX Message Header already contains the Observation   Domain ID (the identifier of the Observation Domain).  If not zero,   this Observation Domain ID can be considered as an implicit scope for   the Data Records in the IPFIX Message.  The Observation Domain ID   MUST be zero when the IPFIX Message contains Data Records with   different Observation Domain ID values defined as scopes.   Multiple Scope Fields MAY be present in the Options Template Record,   in which case, the composite scope is the combination of the scopes.   For example, if the two scopes are defined as "metering process" and   "template", the combined scope is this Template for this Metering   Process.  The order of the Scope Fields, as defined in the Options   Template Record, is irrelevant in this case.  However, if the order   of the Scope Fields in the Options Template Record is relevant, the   order of the Scope Fields MUST be used.  For example, if the first   scope defines the filtering function, while the second scope defines   the sampling function, the order of the scope is important.  Applying   the sampling function first, followed by the filtering function,   would lead to potentially different Data Records than applying the   filtering function first, followed by the sampling function.  In this   case, the Collector deduces the function order by looking at the   order of the scope in the Options Template Record.   The scope is an Information Element specified in the IPFIX   Information Model [RFC5102].  An IPFIX-compliant implementation of   the Collecting Process SHOULD support this minimum set of Information   Elements as scope: LineCardId, TemplateId, exporterIPv4Address,   exporterIPv6Address, and ingressInterface.  Note that other   Information Elements, such as meteringProcessId, exportingProcessId,   observationDomainId, etc. are also valid scopes.  The IPFIX protocol   doesn't prevent the use of any Information Elements for scope.   However, some Information Element types don't make sense if specified   as scope; for example, the counter Information Elements.   Finally, note that the Scope Field Count MUST NOT be zero.Claise, et al.              Standards Track                    [Page 19]

RFC 5101              IPFIX Protocol Specification          January 20083.4.2.2.  Options Template Record Format   An Options Template Record contains any combination of IANA-assigned   and/or enterprise-specific Information Elements identifiers.   The format of the Options Template Record is shown in Figure M.  It   consists of an Options Template Record Header and one or more Field   Specifiers.  The definition of the Field Specifiers is given in   Figure G above.   +--------------------------------------------------+   | Options Template Record Header                   |   +--------------------------------------------------+   | Field Specifier                                  |   +--------------------------------------------------+   | Field Specifier                                  |   +--------------------------------------------------+    ...   +--------------------------------------------------+   | Field Specifier                                  |   +--------------------------------------------------+   Figure M: Options Template Record Format   The format of the Options Template Record Header is shown in Figure   N.    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   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |         Template ID (> 255)   |         Field Count           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |      Scope Field Count        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure N: Options Template Record Header Format   The Options Template Record Header Field Definitions are as follows:   Template ID   Template ID of this Options Template Record.  This value is greater   than 255.Claise, et al.              Standards Track                    [Page 20]

RFC 5101              IPFIX Protocol Specification          January 2008   Field Count   Number of all fields in this Options Template Record, including the   Scope Fields.   Scope Field Count   Number of scope fields in this Options Template Record.  The Scope   Fields are normal Fields except that they are interpreted as scope at   the Collector.  The Scope Field Count MUST NOT be zero.   The example in Figure O shows an Option Template Set with mixed IETF   and enterprise-specific Information Elements.  It consists of a Set   Header, an Option Template Header, and several Field Specifiers.    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 = 3           |          Length               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |         Template ID = 258     |         Field Count = N + M   |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |     Scope Field Count = N     |0|  Scope 1 Infor. Element Id. |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |     Scope 1 Field Length      |0|  Scope 2 Infor. Element Id. |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |     Scope 2 Field Length      |             ...               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |            ...                |1|  Scope N Infor. Element Id. |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |     Scope N Field Length      |   Scope N Enterprise Number ...   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   ...  Scope N Enterprise Number   |1| Option 1 Infor. Element Id. |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |    Option 1 Field Length      |  Option 1 Enterprise Number ...   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   ... Option 1 Enterprise Number   |              ...              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |             ...               |0| Option M Infor. Element Id. |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |     Option M Field Length     |      Padding (optional)       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure O: Option Template Set ExampleClaise, et al.              Standards Track                    [Page 21]

RFC 5101              IPFIX Protocol Specification          January 20083.4.3.  Data Record Format   The Data Records are sent in Data Sets.  The format of the Data   Record is shown in Figure P.  It consists only of one or more Field   Values.  The Template ID to which the Field Values belong is encoded   in the Set Header field "Set ID", i.e., "Set ID" = "Template ID".   +--------------------------------------------------+   | Field Value                                      |   +--------------------------------------------------+   | Field Value                                      |   +--------------------------------------------------+    ...   +--------------------------------------------------+   | Field Value                                      |   +--------------------------------------------------+   Figure P: Data Record Format   Note that Field Values do not necessarily have a length of 16 bits.   Field Values are encoded according to their data type specified in   [RFC5102].   Interpretation of the Data Record format can be done only if the   Template Record corresponding to the Template ID is available at the   Collecting Process.   The example in Figure Q shows a Data Set. It consists of a Set Header   and several Field Values.Claise, et al.              Standards Track                    [Page 22]

RFC 5101              IPFIX Protocol Specification          January 2008    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 = Template ID        |          Length               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Record 1 - Field Value 1    |   Record 1 - Field Value 2    |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Record 1 - Field Value 3    |             ...               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Record 2 - Field Value 1    |   Record 2 - Field Value 2    |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Record 2 - Field Value 3    |             ...               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Record 3 - Field Value 1    |   Record 3 - Field Value 2    |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Record 3 - Field Value 3    |             ...               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |              ...              |      Padding (optional)       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure Q: Data Set, Containing Data Records4.  Specific Reporting Requirements   Some specific Options Templates and Options Template Records are   necessary to provide extra information about the Flow Records and   about the Metering Process.   The Option Template and Options Template Records defined in these   subsections, which impose some constraints on the Metering Process   and Exporting Process implementations, MAY be implemented.  If   implemented, the specific Option Templates SHOULD be implemented as   specified in these subsections.   The minimum set of Information Elements is always specified in these   Specific IPFIX Options Templates.  Nevertheless, extra Information   Elements may be used in these specific Options Templates.4.1.  The Metering Process Statistics Option Template   The Metering Process Statistics Option Template specifies the   structure of a Data Record for reporting Metering Process statistics.   It SHOULD contain the following Information Elements that are defined   in [RFC5102]:Claise, et al.              Standards Track                    [Page 23]

RFC 5101              IPFIX Protocol Specification          January 2008   observationDomainId                           An identifier of an Observation Domain that                           is locally unique to the Exporting Process.                           This Information Element MUST be defined as a                           Scope Field.   exportedMessageTotalCount                           The total number of IPFIX Messages that the                           Exporting Process successfully sent to the                           Collecting Process since the Exporting                           Process re-initialization.   exportedFlowTotalCount                           The total number of Flow Records that the                           Exporting Process successfully sent to the                           Collecting Process since the Exporting                           Process re-initialization.   exportedOctetTotalCount                           The total number of octets that the Exporting                           Process successfully sent to the Collecting                           Process since the Exporting Process re-                           initialization.   The Exporting Process SHOULD export the Data Record specified by the   Metering Process Statistics Option Template on a regular basis or   based on some export policy.  This periodicity or export policy   SHOULD be configurable.   Note that if several Metering Processes are available on the Exporter   Observation Domain, the Information Element meteringProcessId MUST be   specified as an additional Scope Field.4.2.  The Metering Process Reliability Statistics Option Template   The Metering Process Reliability Option Template specifies the   structure of a Data Record for reporting lack of reliability in the   Metering Process.  It SHOULD contain the following Information   Elements that are defined in [RFC5102]:   observationDomainId                           An identifier of an Observation Domain that                           is locally unique to the Exporting Process.                           This Information Element MUST be defined as a                           Scope Field.Claise, et al.              Standards Track                    [Page 24]

RFC 5101              IPFIX Protocol Specification          January 2008   ignoredPacketTotalCount                           The total number of IP packets that the                           Metering Process did not process.   ignoredOctetTotalCount                           The total number of octets in observed IP                           packets that the Metering Process did not                           process.   time first ignored                           The timestamp of the first IP packet that was                           ignored by the Metering Process.  For this                           timestamp, any of the "flowStart" timestamp                           Information Elements flowStartMilliseconds,                           flowStartMicroseconds, flowStartNanoseconds,                           and flowStartDeltaMicroseconds can be used.   time last ignored                           The timestamp of the last IP packet that was                           ignored by the Metering Process.  For this                           timestamp, any of the "flowEnd" timestamp                           Information Elements flowEndMilliseconds,                           flowEndMicroseconds, flowEndNanoseconds, and                           flowEndDeltaMicroseconds can be used.   The Exporting Process SHOULD export the Data Record specified by the   Metering Process Reliability Statistics Option Template on a regular   basis or based on some export policy.  This periodicity or export   policy SHOULD be configurable.   Note that if several Metering Processes are available on the Exporter   Observation Domain, the Information Element meteringProcessId MUST be   specified as an additional Scope Field.4.3.  The Exporting Process Reliability Statistics Option Template   The Exporting Process Reliability Option Template specifies the   structure of a Data Record for reporting lack of reliability in the   Exporting process.  It SHOULD contain the following Information   Elements that are defined in [RFC5102]:   Exporting Process ID                        The identifier of the Exporting Process for                        which lack of reliability is reported.  There                        are three Information Elements specified in                        [RFC5102] that can be used for this purpose:                        exporterIPv4Address, exporterIPv6Address, orClaise, et al.              Standards Track                    [Page 25]

RFC 5101              IPFIX Protocol Specification          January 2008                        exportingProcessId.  This Information Element                        MUST be defined as a Scope Field.   notSentFlowTotalCount                        The total number of Flows that were generated by                        the Metering Process and dropped by the Metering                        Process or by the Exporting Process instead of                        being sent to the Collecting Process.   notSentPacketTotalCount                        The total number of packets in Flow Records that                        were generated by the Metering Process and                        dropped by the Metering Process or by the                        Exporting Process instead of being sent to the                        Collecting Process.   notSentOctetTotalCount                        The total number of octets in packets in Flow                        Records that were generated by the Metering                        Process and dropped by the Metering Process or                        by the Exporting Process instead of being sent                        to the Collecting Process.   time first flow dropped                        The timestamp of the first Flow was dropped by                        the Metering Process.  For this timestamp, any                        of the "flowStart" timestamp Information                        Elements flowStartMilliseconds,                        flowStartMicroseconds, flowStartNanoseconds, and                        flowStartDeltaMicroseconds can be used.   time last flow dropped                        The timestamp of the last IP packet that was                        ignored by the Metering Process.  For this                        timestamp, any of the "flowEnd" timestamp                        Information Elements flowEndMilliseconds,                        flowEndMicroseconds, flowEndNanoseconds, and                        flowEndDeltaMicroseconds can be used.   The Exporting Process SHOULD export the Data Record specified by the   Exporting Process Reliability Statistics Option Template on a regular   basis or based on some export policy.  This periodicity or export   policy SHOULD be configurable.4.4.  The Flow Keys Option Template   The Flow Keys Option Template specifies the structure of a Data   Record for reporting the Flow Keys of reported Flows.  A Flow KeysClaise, et al.              Standards Track                    [Page 26]

RFC 5101              IPFIX Protocol Specification          January 2008   Data Record extends a particular Template Record that is referenced   by its templateId identifier.  The Template Record is extended by   specifying which of the Information Elements contained in the   corresponding Data Records describe Flow properties that serve as   Flow Keys of the reported Flow.   The Flow Keys Option Template SHOULD contain the following   Information Elements that are defined in [RFC5102]:   templateId              An identifier of a Template.  This                           Information Element MUST be defined as a                           Scope Field.   flowKeyIndicator        Bitmap with the positions of the Flow Keys in                           the Data Records.5.  IPFIX Message Header "Export Time" and Flow Record Time   The IPFIX Message Header "Export Time" field is the time in seconds   since 0000 UTC Jan 1, 1970, at which the IPFIX Message Header leaves   the Exporter.  The time-related Information Elements specified in   [RFC5102] MAY use this "Export Time" as base time and specify an   offset relative to it, instead of using a common base time, such as   0000 UTC Jan 1, 1970.  All Information Elements that do not have   their base time defined by their data type MUST have the base time   clearly specified in their description.   For example, Data Records requiring a microsecond precision can   export the flow start and end times with the flowStartMicroseconds   and flowEndMicroseconds Information Elements [RFC5102], containing   the time since 0000 UTC Jan 1, 1970.  An alternate solution is to   export the flowStartDeltaMicroseconds and flowEndDeltaMicroseconds   Information Elements [RFC5102] in the Data Record, which respectively   report the flow start and end time offsets compared to the IPFIX   Message Header "Export Time".  The latter solution lowers the export   bandwidth requirement while it increases the load on the Exporter, as   the Exporting Process must calculate the flowStartDeltaMicroseconds   and flowEndDeltaMicroseconds of every single Data Record before   exporting the IPFIX Message.   It must be noted that using time-related Information Elements with   offset times, compared to the IPFIX Message Header "Export Time",   imposes some time constraints on the Data Records contained in the   IPFIX Message.  In the example of flowStartDeltaMicroseconds and   flowEndDeltaMicroseconds Information Elements [RFC5102], the Data   Record must be exported within a maximum of 71 minutes after its   creation.  Otherwise, the 32-bit counter would not be sufficient to   contain the flow start time offset.Claise, et al.              Standards Track                    [Page 27]

RFC 5101              IPFIX Protocol Specification          January 20086.  Linkage with the Information Model   The Information Elements [RFC5102] MUST be sent in canonical format   in network-byte order (also known as the big-endian byte ordering).6.1.  Encoding of IPFIX Data Types   The following sections will define the encoding of the data types   specified in [RFC5102].6.1.1.  Integral Data Types   Integral data types -- octet, signed8, unsigned16, signed16,   unsigned32, signed32, signed64, and unsigned64 -- MUST be encoded   using the default canonical format in network-byte order.  Signed   Integral data types are represented in two's complement notation.6.1.2.  Address Types   Address types -- macAddress, ipv4Address, and ipv6Address -- MUST be   encoded the same way as the integral data types.  The macAddress is   treated as a 6-octet integer, the ipv4Address as a 4-octet integer,   and the ipv6Address as a 16-octet integer.6.1.3.  float32   The float32 data type MUST be encoded as an IEEE single-precision   32-bit floating point-type, as specified in [IEEE.754.1985].6.1.4.  float64   The float64 data type MUST be encoded as an IEEE double-precision   64-bit floating point-type, as specified in [IEEE.754.1985].6.1.5.  boolean   The boolean data type is specified according to the TruthValue in   [RFC2579]: it is an integer with the value 1 for true and a value 2   for false.  Every other value is undefined.  The boolean data type   MUST be encoded in a single octet.6.1.6.  string and octetarray   The data type string represents a finite length string of valid   characters of the Unicode character encoding set.  The string data   type MUST be encoded in UTF-8 format.  The string is sent as an array   of octets using an Information Element of fixed or variable length.Claise, et al.              Standards Track                    [Page 28]

RFC 5101              IPFIX Protocol Specification          January 2008   The length of the Information Element specifies the length of the   octetarray.6.1.7.  dateTimeSeconds   The data type dateTimeseconds represents a time value in units of   seconds normalized to the GMT timezone.  It MUST be encoded in a   32-bit integer containing the number of seconds since 0000 UTC Jan 1,   1970.  The 32-bit integer allows the time encoding up to 136 years.6.1.8.  dateTimeMilliseconds   The data type dateTimeMilliseconds represents a time value in units   of milliseconds normalized to the GMT timezone.  It MUST be encoded   in a 64-bit integer containing the number of milliseconds since 0000   UTC Jan 1, 1970.6.1.9.  dateTimeMicroseconds   The data type dateTimeMicroseconds represents a time value in units   of microseconds normalized to the GMT timezone.  It MUST be encoded   in a 64-bit integer, according to the NTP format given in [RFC1305].6.1.10.  dateTimeNanoseconds   The data type of dateTimeNanoseconds represents a time value in units   of nanoseconds normalized to the GMT time zone.  It MUST be encoded   in a 64-bit integer, according to the NTP format given in [RFC1305].6.2.  Reduced Size Encoding of Integer and Float Types   Information Elements containing integer, string, float, and   octetarray types in the information model MAY be encoded using fewer   octets than those implied by their type in the information model   definition [RFC5102], based on the assumption that the smaller size   is sufficient to carry any value the Exporter may need to deliver.   This reduces the network bandwidth requirement between the Exporter   and the Collector.  Note that the Information Element definitions   [RFC5102] will always define the maximum encoding size.   For instance, the information model [RFC5102] defines byteCount as an   unsigned64 type, which would require 64 bits.  However, if the   Exporter will never locally encounter the need to send a value larger   than 4294967295, it may chose to send the value instead as an   unsigned32.  For example, a core router would require an unsigned64   byteCount, while an unsigned32 might be sufficient for an access   router.Claise, et al.              Standards Track                    [Page 29]

RFC 5101              IPFIX Protocol Specification          January 2008   This behavior is indicated by the Exporter by specifying a type size   with a smaller length than that associated with the assigned type of   the Information Element.  In the example above, the Exporter would   place a length of 4 versus 8 in the Template.   If reduced sizing is used, it MUST only be applied to the following   integer types: unsigned64, signed64, unsigned32, signed32,   unsigned16, and signed16.  The signed versus unsigned property of the   reported value MUST be preserved.  The reduction in size can be to   any number of octets smaller than the original type if the data value   still fits, i.e., so that only leading zeroes are dropped.  For   example, an unsigned64 can be reduced in size to 7, 6, 5, 4, 3, 2, or   1 octet(s).   Reduced sizing can also be used to reduce float64 to float32.  The   float32 not only has a reduced number range, but due to the smaller   mantissa, is also less precise.   The reduced size encoding MUST NOT be applied to dateTimeMicroseconds   or to dateTimeNanoseconds because these represent an inherent   structure that would be destroyed by using less than the original   number of bytes.7.  Variable-Length Information Element   The IPFIX Template mechanism is optimized for fixed-length   Information Elements [RFC5102].  Where an Information Element has a   variable length, the following mechanism MUST be used to carry the   length information for both the IETF and proprietary Information   Elements.   In the Template Set, the Information Element Field Length is recorded   as 65535.  This reserved length value notifies the Collecting Process   that length of the Information Element will be carried in the   Information Element content itself.   In most cases, the length of the Information Element will be less   than 255 octets.  The following length-encoding mechanism optimizes   the overhead of carrying the Information Element length in this   majority case.  The length is carried in the octet before the   Information Element, as shown in Figure R.Claise, et al.              Standards Track                    [Page 30]

RFC 5101              IPFIX Protocol Specification          January 2008    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   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   | Length (< 255)|          Information Element                  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                      ... continuing as needed                 |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure R: Variable-Length Information Element (length < 255 octets)   If the length of the Information Element is greater than or equal to   255 octets, the length is encoded into 3 octets before the   Information Element.  The first octet is 255, and the length is   carried in the second and third octets, as shown in Figure S.    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 65535)      |       IE      |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                      ... continuing as needed                 |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure S: Variable-Length Information Element (length 0 to 65535   octets)   The octets carrying the length (either the first or the first three   octets) MUST NOT be included in the length of the Information   Element.8.  Template Management   This section describes Template Management when using SCTP and   PR-SCTP as the transport protocol.  Any necessary changes to Template   Management specifically related to TCP or UDP transport protocols are   specified inSection 10.   The Exporting Process assigns and maintains the Template IDs per SCTP   association for the Exporter's Observation Domains.  A newly created   Template Record is assigned an unused Template ID by the Exporting   Process.   If a specific Information Element is required by a Template, but is   not available in observed packets, the Exporting Process MAY choose   to export Flow Records without this Information Element in a Data   Record defined by a new Template.Claise, et al.              Standards Track                    [Page 31]

RFC 5101              IPFIX Protocol Specification          January 2008   If an Information Element is required more than once in a Template,   the different occurrences of this Information Element SHOULD follow   the logical order of their treatments by the Metering Process.  For   example, if a selected packet goes through two hash functions, and if   the two hash values are sent within a single Template, the first   occurrence of the hash value should belong to the first hash function   in the Metering Process.  For example, when exporting the two source   IP addresses of an IPv4 in IPv4 packets, the first sourceIPv4Address   Information Element occurrence should be the IPv4 address of the   outer header, while the second occurrence should be the inner header   one.   Template Sets and Options Template Sets may be sent on any SCTP   stream.  Template Sets and Options Template Sets MUST be sent   reliably, using SCTP-ordered delivery.  As such, the Collecting   Process MUST store the Template Record information for the duration   of the SCTP association so that it can interpret the corresponding   Data Records that are received in subsequent Data Sets.   The Exporting Process SHOULD transmit the Template Set and Options   Template Set in advance of any Data Sets that use that (Options)   Template ID, to help ensure that the Collector has the Template   Record before receiving the first Data Record.  Data Records that   correspond to a Template Record MAY appear in the same and/or   subsequent IPFIX Message(s).   Different Observation Domains from the same SCTP association may use   the same Template ID value to refer to different Templates.   The Templates that are not used anymore SHOULD be deleted.  Before   reusing a Template ID, the Template MUST be deleted.  In order to   delete an allocated Template, the Template is withdrawn through the   use of a Template Withdrawal Message.   The Template Withdrawal Message MUST NOT be sent until sufficient   time has elapsed to allow the Collecting Process to receive and   process the last Data Record using this Template information.  This   time MUST be configurable.  A suitable default value is 5 seconds   after the last Data Record has been sent.   The Template ID from a withdrawn Template MUST NOT be reused until   sufficient time has elapsed to allow for the Collecting Process to   receive and process the Template Withdrawal Message.   A Template Withdrawal Message is a Template Record for that Template   ID with a Field Count of 0.  The format of the Template Withdrawal   Message is shown in Figure T.Claise, et al.              Standards Track                    [Page 32]

RFC 5101              IPFIX Protocol Specification          January 2008    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 = (2 or 3)       |          Length = 16          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |          Template ID N        |        Field Count = 0        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |          Template ID ...      |        Field Count = 0        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |          Template ID M        |        Field Count = 0        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure T: Template Withdrawal Message Format   The Set ID field MUST contain the value 2 for Template Set Withdrawal   and the value 3 for Options Template Set Withdrawal.  Multiple   Template IDs MAY be withdrawn with a single Template Withdrawal   Message, in that case, padding MAY be used.   The Template Withdrawal Message withdraws the Template IDs for the   Observation Domain ID specified in the IPFIX Message Header.   The Template Withdrawal Message may be sent on any SCTP stream.  The   Template Withdrawal Message MUST be sent reliably, using SCTP-ordered   delivery.   The Template Withdrawal Message MUST NOT contain new Template or   Options Template Records.   If the measurement parameters change such that a new Template is   required, the Template MUST be withdrawn (using a Template Withdraw   Message and a new Template definition) or an unused Template ID MUST   be used.  Examples of the measurement changes are: a new sampling   rate, a new Flow expiration process, a new filtering definition, etc.   When the SCTP association shuts down or the Exporting Process   restarts, all Template assignments are lost and Template IDs MUST be   reassigned.   If the Metering Process restarts, the Exporting Process MUST either   reuse the previously assigned Template ID for each Template, or it   MUST withdraw the previously issued Template IDs by sending Template   Withdraw Message(s) before reusing them.   A Template Withdrawal Message to withdraw all Templates for the   Observation Domain ID specified in the IPFIX Message Header MAY be   used.  Its format is shown in Figure U.Claise, et al.              Standards Track                    [Page 33]

RFC 5101              IPFIX Protocol Specification          January 2008    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 = 2        |          Length = 8           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |         Template ID = 2       |        Field Count = 0        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure U: All Data Templates Withdrawal Message Format   A Template Withdrawal Message to withdraw all Options Templates for   the Observation Domain ID specified in the IPFIX Message Header MAY   be used.  Its format is shown in Figure V.    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 = 3        |          Length = 8           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |         Template ID = 3       |        Field Count = 0        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Figure V: All Options Templates Withdrawal Message Format   When the SCTP association restarts, the Exporting Process MUST resend   all the Template Records.9.  The Collecting Process's Side   This section describes the Collecting Process when using SCTP and   PR-SCTP as the transport protocol.  Any necessary changes to the   Collecting Process specifically related to TCP or UDP transport   protocols are specified inSection 10.   The Collecting Process SHOULD listen for a new association request   from the Exporting Process.  The Exporting Process will request a   number of streams to use for export.  An Exporting Process MAY   request and support more than one stream per SCTP association.   If the Collecting Process receives a malformed IPFIX Message, it MUST   reset the SCTP association, discard the IPFIX Message, and SHOULD log   the error.  Note that non-zero Set padding does not constitute a   malformed IPFIX Message.   Template Sets and Option Template Sets are only sent once.  The   Collecting Process MUST store the Template Record information for the   duration of the association so that it can interpret the   corresponding Data Records that are received in subsequent Data Sets.Claise, et al.              Standards Track                    [Page 34]

RFC 5101              IPFIX Protocol Specification          January 2008   Template IDs are unique per SCTP association and per Observation   Domain.  If the Collecting Process receives a Template that has   already been received but that has not previously been withdrawn   (i.e., a Template Record from the same Exporter Observation Domain   with the same Template ID received on the SCTP association), then the   Collecting Process MUST shut down the association.   When an SCTP association is closed, the Collecting Process MUST   discard all Templates received over that association and stop   decoding IPFIX Messages that use those Templates.   The Collecting Process normally receives Template Records from the   Exporting Process before receiving Data Records.  The Data Records   are then decoded and stored by the Collector.  If the Template   Records have not been received at the time Data Records are received,   the Collecting Process MAY store the Data Records for a short period   of time and decode them after the Template Records are received.  A   Collecting Process MUST NOT assume that the Data Set and the   associated Template Set (or Options Template Set) are exported in the   same IPFIX Message.   The Collecting Process MUST note the Information Element identifier   of any Information Element that it does not understand and MAY   discard that Information Element from the Flow Record.   The Collector MUST accept padding in Data Records and Template   Records.  The padding size is the Set Length minus the size of the   Set Header (4 octets for the Set ID and the Set Length), modulo the   Record size deduced from the Template Record.   The IPFIX protocol has a Sequence Number field in the Export header   that increases with the number of IPFIX Data Records in the IPFIX   Message.  A Collector may detect out-of-sequence, dropped, or   duplicate IPFIX Messages by tracking the Sequence Number.  A   Collector SHOULD provide a logging mechanism for tracking   out-of-sequence IPFIX Messages.  Such out-of-sequence IPFIX Messages   may be due to Exporter resource exhaustion where it cannot transmit   messages at their creation rate, an Exporting Process reset,   congestion on the network link between the Exporter and Collector,   Collector resource exhaustion where it cannot process the IPFIX   Messages at their arrival rate, out-of-order packet reception,   duplicate packet reception, or an attacker injecting false messages.   If a Collecting Process receives a Template Withdrawal Message, the   Collecting Process MUST delete the corresponding Template Records   associated with the specific SCTP association and specific   Observation Domain, and stop decoding IPFIX Messages that use the   withdrawn Templates.Claise, et al.              Standards Track                    [Page 35]

RFC 5101              IPFIX Protocol Specification          January 2008   If the Collecting Process receives a Template Withdraw message for a   Template Record it has not received before on this SCTP association,   it MUST reset the SCTP association, discard the IPFIX Message, and   SHOULD log the error as it does for malformed IPFIX Messages.   A Collecting Process that receives IPFIX Messages from several   Observation Domains on the same Transport Session MUST be aware that   the uniqueness of the Template ID is not guaranteed across   Observation Domains.   The Collector MUST support the use of Templates containing multiple   occurrences of the similar Information Elements.10.  Transport Protocol   The IPFIX Protocol Specification has been designed to be transport   protocol independent.  Note that the Exporter can export to multiple   Collecting Processes using independent transport protocols.   The IPFIX Message Header 16-bit Length field limits the length of an   IPFIX Message to 65535 octets, including the header.  A Collecting   Process MUST be able to handle IPFIX Message lengths of up to 65535   octets.10.1.  Transport Compliance and Transport Usage   We need to differentiate between what must be implemented (so that   operators can interoperably deploy compliant implementations from   different vendors) and what should or could be used in various   operational environments.  We must also make sure that ALL   implementations can operate in a congestion-aware and   congestion-avoidance mode.   SCTP [RFC4960] using the PR-SCTP extension specified in [RFC3758]   MUST be implemented by all compliant implementations.  UDP [UDP] MAY   also be implemented by compliant implementations.  TCP [TCP] MAY also   be implemented by compliant implementations.   PR-SCTP SHOULD be used in deployments where Exporters and Collectors   are communicating over links that are susceptible to congestion.   PR-SCTP is capable of providing any required degree of reliability.   TCP MAY be used in deployments where Exporters and Collectors   communicate over links that are susceptible to congestion, but   PR-SCTP is preferred due to its ability to limit back pressure on   Exporters and its message versus stream orientation.Claise, et al.              Standards Track                    [Page 36]

RFC 5101              IPFIX Protocol Specification          January 2008   UDP MAY be used, although it is not a congestion-aware protocol.   However, the IPFIX traffic between Exporter and Collector MUST run in   an environment where IPFIX traffic has been provisioned for, or is   contained through some other means.10.2.  SCTP   This section describes how IPFIX can be transported over SCTP   [RFC4960] using the PR-SCTP [RFC3758] extension.10.2.1.  Congestion Avoidance   The SCTP transport protocol provides the required level of congestion   avoidance by design.   SCTP will detect congestion in the end-to-end path between the IPFIX   Exporting Process and the IPFIX Collecting Process, and limit the   transfer rate accordingly.  When an IPFIX Exporting Process has   records to export, but detects that transmission by SCTP is   temporarily impossible, it can either wait until sending is possible   again, or it can decide to drop the record.  In the latter case, the   dropped export data MUST be accounted for, so that the amount of   dropped export data can be reported.10.2.2.  Reliability   The SCTP transport protocol is by default reliable, but has the   capability to deliver messages with partial reliability  [RFC3758].   Using reliable SCTP messages for the IPFIX export is not in itself a   guarantee that all Data Records will be delivered.  If there is   congestion on the link from the Exporting Process to the Collecting   Process, or if a significant number of retransmissions are required,   the send queues on the Exporting Process may fill up; the Exporting   Process MAY either suspend, export, or discard the IPFIX Messages.   If Data Records are discarded the IPFIX Sequence Numbers used for   export MUST reflect the loss of data.10.2.3.  MTU   SCTP provides the required IPFIX Message fragmentation service based   on path MTU discovery.Claise, et al.              Standards Track                    [Page 37]

RFC 5101              IPFIX Protocol Specification          January 200810.2.4.  Exporting Process10.2.4.1.  Association Establishment   The IPFIX Exporting Process SHOULD initiate an SCTP association with   the IPFIX Collecting Process.  By default, the Collecting Process   listens for connections on SCTP port 4739.  By default, the   Collecting Process listens for secure connections on SCTP port 4740   (refer to the Security Considerations section).  By default, the   Exporting Process tries to connect to one of these ports.  It MUST be   possible to configure both the Exporting and Collecting Processes to   use a different SCTP port.   The Exporting Process MAY establish more than one association   (connection "bundle" in SCTP terminology) to the Collecting Process.   An Exporting Process MAY support more than one active association to   different Collecting Processes (including the case of different   Collecting Processes on the same host).10.2.4.2.   Association Shutdown   When an Exporting Process is shut down, it SHOULD shut down the SCTP   association.   When a Collecting Process no longer wants to receive IPFIX Messages,   it SHOULD shut down its end of the association.  The Collecting   Process SHOULD continue to receive and process IPFIX Messages until   the Exporting Process has closed its end of the association.   When a Collecting Process detects that the SCTP association has been   abnormally terminated, it MUST continue to listen for a new   association establishment.   When an Exporting Process detects that the SCTP association to the   Collecting Process is abnormally terminated, it SHOULD try to   re-establish the association.   Association timeouts SHOULD be configurable.10.2.4.3.  Stream   An Exporting Process MAY request more than one SCTP stream per   association.  Each of these streams may be used for the transmission   of IPFIX Messages containing Data Sets, Template Sets, and/or Options   Template Sets.Claise, et al.              Standards Track                    [Page 38]

RFC 5101              IPFIX Protocol Specification          January 2008   Depending on the requirements of the application, the Exporting   Process may send Data Sets with full or partial reliability, using   ordered or out-of-order delivery, over any SCTP stream established   during SCTP Association setup.   An IPFIX Exporting Process MAY use any PR-SCTP Service Definition as   perSection 4 of the PR-SCTP [RFC3758] specification when using   partial reliability to transmit IPFIX Messages containing only Data   Sets.   However, Exporting Processes SHOULD mark such IPFIX Messages for   retransmission for as long as resource or other constraints allow.10.2.4.4.  Template Management   When the transport protocol is SCTP, the default Template Management   described inSection 8 is used.10.2.5.  Collecting Process   When the transport protocol is SCTP, the default Collector processing   described inSection 9 is used.10.2.6.  Failover   If the Collecting Process does not acknowledge the attempt by the   Exporting Process to establish an association, the Exporting Process   should retry using the SCTP exponential backoff feature.  The   Exporter MAY log an alarm if the time to establish the association   exceeds a specified threshold, configurable on the Exporter.   If Collecting Process failover is supported by the Exporting Process,   a second SCTP association MAY be opened in advance.10.3.  UDP   This section describes how IPFIX can be transported over UDP [UDP].10.3.1.  Congestion Avoidance   UDP has no integral congestion-avoidance mechanism.  Its use over   congestion-sensitive network paths is therefore not recommended.  UDP   MAY be used in deployments where Exporters and Collectors always   communicate over dedicated links that are not susceptible to   congestion, i.e., over provisioned links compared to the maximum   export rate from the Exporters.Claise, et al.              Standards Track                    [Page 39]

RFC 5101              IPFIX Protocol Specification          January 200810.3.2.  Reliability   UDP is not a reliable transport protocol, and cannot guarantee   delivery of messages.  IPFIX Messages sent from the Exporting Process   to the Collecting Process using UDP may therefore be lost.  UDP MUST   NOT be used unless the application can tolerate some loss of IPFIX   Messages.   The Collecting Process SHOULD deduce the loss and reordering of IPFIX   Data Records by looking at the discontinuities in the IPFIX Sequence   Number.  In the case of UDP, the IPFIX Sequence Number contains the   total number of IPFIX Data Records sent for the UDP Transport Session   prior to the receipt of this IPFIX Message, modulo 2^32.  A Collector   SHOULD detect out-of-sequence, dropped, or duplicate IPFIX Messages   by tracking the Sequence Number.  Templates sent from the Exporting   Process to the Collecting Process using UDP as a transport MUST be   re-sent at regular intervals, in case previous copies were lost.10.3.3.  MTU   The maximum size of exported messages MUST be configured such that   the total packet size does not exceed the path MTU.  If the path MTU   is unknown, a maximum packet size of 512 octets SHOULD be used.10.3.4.  Port Numbers   By default, the Collecting Process listens on the UDP port 4739.  By   default, the Collecting Process listens for secure connections on UDP   port 4740 (refer to the "Security Considerations" section).  By   default, the Exporting Process tries to connect to one of these   ports.  It MUST be possible to configure both the Exporting and   Collecting Processes to use a different UDP port.10.3.5.  Exporting Process   The Exporting Process MAY duplicate the IPFIX Message to the several   Collecting Processes.10.3.6.  Template Management   When IPFIX uses UDP as the transport protocol, Template Sets and   Option Template Sets MUST be re-sent at regular intervals.  The   frequency of the (Options) Template transmission MUST be   configurable.  The default value for the frequency of the (Options)   Template transmission is 10 minutes.  The Exporting Process SHOULD   transmit the Template Set and Options Template Set in advance of any   Data Sets that use that (Options) Template ID to help ensure that theClaise, et al.              Standards Track                    [Page 40]

RFC 5101              IPFIX Protocol Specification          January 2008   Collector has the Template Record before receiving the first Data   Record.   In the event of configuration changes, the Exporting Process SHOULD   send multiple copies of the new Template definitions, in different   IPFIX Messages, at an accelerated rate.  In such a case, it SHOULD   transmit the changed Template Record(s) and Options Template   Record(s), without any data, in advance to help ensure that the   Collector will have the correct Template information before receiving   the first data.   If the Option Template scope is defined in another Template, then   both Templates SHOULD be sent in the same IPFIX Message.  For   example, if a Flow Key Option Template (seeSection 4.4) is sent in   an Option Template, then the associated Template SHOULD be sent in   the same IPFIX Message.   Following a configuration change that can modify the interpretation   of the Data Records (for example, a sampling rate change) a new   Template ID MUST be used, and the old Template ID MUST NOT be reused   until its lifetime (seeSection 10.3.7) has expired.   If UDP is selected as the transport protocol, the Template Withdraw   Messages MUST NOT be used, as this method is inefficient due to the   unreliable nature of UDP.10.3.7.  Collecting Process   The Collecting Process MUST associate a lifetime with each Template   (or another definition of an identifier considered unique within the   Transport Session) received via UDP.  Templates (and similar   definitions) not refreshed by the Exporting Process within the   lifetime are expired at the Collecting Process.  If the Template (or   other definition) is not refreshed before that lifetime has expired,   the Collecting Process MUST discard that definition and any current   and future associated Data Records.  In which case, an alarm MUST be   logged.  The Collecting Process MUST NOT decode any further Data   Records that are associated with the expired Template.  If a Template   is refreshed with a Template Record that differs from the previously   received Template Record, the Collecting Process SHOULD log a warning   and replace the previously received Template Record with the new one.   The Template lifetime at the Collecting Process MUST be at least 3   times higher than the Template refresh timeout configured on the   Exporting Process.   Template IDs are unique per UDP session and per Observation Domain.   At any given time, the Collecting Process SHOULD maintain the   following for all the current Template Records and Options TemplateClaise, et al.              Standards Track                    [Page 41]

RFC 5101              IPFIX Protocol Specification          January 2008   Records: <IPFIX Device, Exporter source UDP port, Observation Domain   ID, Template ID, Template Definition, Last Received>.   The Collecting Process SHOULD accept Data Records without the   associated Template Record (or other definitions) required to decode   the Data Record.  If the Template Records (or other definitions such   as Common Properties) have not been received at the time Data Records   are received, the Collecting Process SHOULD store the Data Records   for a short period of time and decode them after the Template Records   (or other definitions) are received.  The short period of time MUST   be lower than the lifetime of definitions associated with identifiers   considered unique within the UDP session.   If the Collecting Process receives a malformed IPFIX Message, it MUST   discard the IPFIX Message and SHOULD log the error.10.3.8.  Failover   Because UDP is not a connection-oriented protocol, the Exporting   Process is unable to determine from the transport protocol that the   Collecting Process is no longer able to receive the IPFIX Messages.   Therefore, it cannot invoke a failover mechanism.  However, the   Exporting Process MAY duplicate the IPFIX Message to several   Collecting Processes.10.4.  TCP   This section describes how IPFIX can be transported over TCP [TCP].10.4.1.  Connection Management10.4.1.1.  Connection Establishment   The IPFIX Exporting Process initiates a TCP connection to the   Collecting Process.  By default, the Collecting Process listens for   connections on TCP port 4739.  By default, the Collecting Process   listens for secure connections on TCP port 4740 (refer to the   Security Considerations section).  By default, the Exporting Process   tries to connect to one of these ports.  It MUST be possible to   configure both the Exporting Process and the Collecting Process to   use a different TCP port.   An Exporting Process MAY support more than one active connection to   different Collecting Processes (including the case of different   Collecting Processes on the same host).   The Exporter MAY log an alarm if the time to establish the connection   exceeds a specified threshold, configurable on the Exporter.Claise, et al.              Standards Track                    [Page 42]

RFC 5101              IPFIX Protocol Specification          January 200810.4.1.2.  Graceful Connection Release   When an Exporting Process is shut down, it SHOULD shut down the TCP   connection.   When a Collecting Process no longer wants to receive IPFIX Messages,   it SHOULD close its end of the connection.  The Collecting Process   SHOULD continue to read IPFIX Messages until the Exporting Process   has closed its end.10.4.1.3.  Restarting Interrupted Connections   When a Collecting Process detects that the TCP connection to the   Exporting Process has terminated abnormally, it MUST continue to   listen for a new connection.   When an Exporting Process detects that the TCP connection to the   Collecting Process has terminated abnormally, it SHOULD try to   re-establish the connection.  Connection timeouts and retry schedules   SHOULD be configurable.  In the default configuration, an Exporting   Process MUST NOT attempt to establish a connection more frequently   than once per minute.10.4.1.4.  Failover   If the Collecting Process does not acknowledge the attempt by the   Exporting Process to establish a connection, it will retry using the   TCP exponential backoff feature.   If Collecting Process failover is supported by the Exporting Process,   a second TCP connection MAY be opened in advance.10.4.2.  Data Transmission   Once a TCP connection is established, the Exporting Process starts   sending IPFIX Messages to the Collecting Process.10.4.2.1.  IPFIX Message Encoding   IPFIX Messages are sent over the TCP connection without any special   encoding.  The Length field in the IPFIX Message Header defines the   end of each IPFIX Message and thus the start of the next IPFIX   Message.  This means that IPFIX Messages cannot be interleaved.   In the case of TCP, the IPFIX Sequence Number contains the total   number of IPFIX Data Records sent from this TCP connection, from the   current Observation Domain by the Exporting Process, prior to the   receipt of this IPFIX Message, modulo 2^32.Claise, et al.              Standards Track                    [Page 43]

RFC 5101              IPFIX Protocol Specification          January 2008   If an Exporting Process exports data from multiple Observation   Domains, it should be careful to choose IPFIX Message lengths   appropriately to minimize head-of-line blocking between different   Observation Domains.  Multiple TCP connections MAY be used to avoid   head-of-line between different Observation Domains.10.4.2.2.  Template Management   For each Template, the Exporting Process MUST send the Template   Record before exporting Data Records that refer to that Template.   Template IDs are unique per TCP connection and per Observation   Domain.  A Collecting Process MUST record all Template and Options   Template Records for the duration of the connection, as an Exporting   Process is not required to re-export Template Records.   When the TCP connection restarts, the Exporting Process MUST resend   all the Template Records.   When a TCP connection is closed, the Collecting Process MUST discard   all Templates received over that connection and stop decoding IPFIX   Messages that use those Templates.   The Templates that are not used anymore SHOULD be deleted.  Before   reusing a Template ID, the Template MUST be deleted.  In order to   delete an allocated Template, the Template is withdrawn through the   use of a Template Withdrawal Message over the TCP connection.   If the Collecting Process receives a malformed IPFIX Message, it MUST   reset the TCP connection, discard the IPFIX Message, and SHOULD log   the error.10.4.2.3.  Congestion Handling and Reliability   TCP ensures reliable delivery of data from the Exporting Process to   the Collecting Process.  TCP also controls the rate at which data can   be sent from the Exporting Process to the Collecting Process, using a   mechanism that takes into account both congestion in the network and   the capabilities of the receiver.   Therefore, an IPFIX Exporting Process may not be able to send IPFIX   Messages at the rate that the Metering Process generates it, either   because of congestion in the network or because the Collecting   Process cannot handle IPFIX Messages fast enough.  As long as   congestion is transient, the Exporting Process can buffer IPFIX   Messages for transmission.  But such buffering is necessarily   limited, both because of resource limitations and because ofClaise, et al.              Standards Track                    [Page 44]

RFC 5101              IPFIX Protocol Specification          January 2008   timeliness requirements, so ongoing and/or severe congestion may lead   to a situation where the Exporting Process is blocked.   When an Exporting Process has Data Records to export but the   transmission buffer is full, and it wants to avoid blocking, it can   decide to drop some Data Records.  The dropped Data Records MUST be   accounted for, so that the amount can later be exported.   When an Exporting Process finds that the rate at which records should   be exported is consistently higher than the rate at which TCP sending   permits, it should provide back pressure to the Metering Processes.   The Metering Process could then adapt by temporarily reducing the   amount of data it generates, for example, using sampling or   aggregation.10.4.3.  Collecting Process   The Collecting Process SHOULD listen for a new TCP connection from   the Exporting Process.   If the Collecting Process receives a malformed IPFIX Message, it MUST   reset the TCP connection, discard the IPFIX Message, and SHOULD log   the error.  Note that non-zero Set padding does not constitute a   malformed IPFIX Message.   Template Sets and Option Template Sets are only sent once.  The   Collecting Process MUST store the Template Record information for the   duration of the connection so that it can interpret the corresponding   Data Records that are received in subsequent Data Sets.   Template IDs are unique per TCP connection and per Observation   Domain.  If the Collecting Process receives a Template that has   already been received but that has not previously been withdrawn   (i.e., a Template Record from the same Exporter Observation Domain   with the same Template ID received on the TCP connection), then the   Collecting Process MUST shut down the connection.   When a TCP connection is closed, the Collecting Process MUST discard   all Templates received over that connection and stop decoding IPFIX   Messages that use those Templates.   If a Collecting Process receives a Template Withdrawal Message, the   Collecting Process MUST delete the corresponding Template Records   associated with the specific TCP connection and specific Observation   Domain, and stop decoding IPFIX Messages that use the withdrawn   Templates.Claise, et al.              Standards Track                    [Page 45]

RFC 5101              IPFIX Protocol Specification          January 2008   If the Collecting Process receives a Template Withdrawal Message for   a Template Record it has not received before on this TCP connection,   it MUST reset the TCP association, discard the IPFIX Message, and   SHOULD log the error as it does for malformed IPFIX Messages.11.  Security Considerations   The security considerations for the IPFIX protocol have been derived   from an analysis of potential security threats, as discussed in the   "Security Considerations" section of IPFIX requirements [RFC3917].   The requirements for IPFIX security are as follows:   1. IPFIX must provide a mechanism to ensure the confidentiality of      IPFIX data transferred from an Exporting Process to a Collecting      Process, in order to prevent disclosure of Flow Records      transported via IPFIX.   2. IPFIX must provide a mechanism to ensure the integrity of IPFIX      data transferred from an Exporting Process to a Collecting      Process, in order to prevent the injection of incorrect data or      control information (e.g., Templates) into an IPFIX Message      stream.   3. IPFIX must provide a mechanism to authenticate IPFIX Collecting      and Exporting Processes, to prevent the collection of data from an      unauthorized Exporting Process or the export of data to an      unauthorized Collecting Process.   Because IPFIX can be used to collect information for network   forensics and billing purposes, attacks designed to confuse, disable,   or take information from an IPFIX collection system may be seen as a   prime objective during a sophisticated network attack.   An attacker in a position to inject false messages into an IPFIX   Message stream can either affect the application using IPFIX (by   falsifying data), or the IPFIX Collecting Process itself (by   modifying or revoking Templates, or changing options); for this   reason, IPFIX Message integrity is important.   The IPFIX Messages themselves may also contain information of value   to an attacker, including information about the configuration of the   network as well as end-user traffic and payload data, so care must be   taken to confine their visibility to authorized users.  When an   Information Element containing end-user payload information is   exported, it SHOULD be transmitted to the Collecting Process using a   means that secures its contents against eavesdropping.  Suitable   mechanisms include the use of either a direct point-to-point   connection or the use of an encryption mechanism.  It is theClaise, et al.              Standards Track                    [Page 46]

RFC 5101              IPFIX Protocol Specification          January 2008   responsibility of the Collecting Process to provide a satisfactory   degree of security for this collected data, including, if necessary,   anonymization of any reported data.11.1.  Applicability of TLS and DTLS   Transport Layer Security (TLS) [RFC4346] and Datagram Transport Layer   Security (DTLS) [RFC4347] were designed to provide the   confidentiality, integrity, and authentication assurances required by   the IPFIX protocol, without the need for pre-shared keys.   With the mandatory SCTP and PR-SCTP transport protocols for IPFIX,   DTLS [RFC4347] MUST be implemented.  If UDP is selected as the IPFIX   transport protocol, DTLS [RFC4347] MUST be implemented.  If TCP is   selected as the IPFIX transport protocol, TLS [RFC4346] MUST be   implemented.   Note that DTLS is selected as the security mechanism for SCTP and   PR-SCTP.  Though TLS bindings to SCTP are defined in [RFC3436], they   require all communication to be over reliable, bidirectional streams,   and require one TLS connection per stream.  This arrangement is not   compatible with the rationale behind the choice of SCTP as an IPFIX   transport protocol.   Note that using DTLS [RFC4347] has a vulnerability, i.e., a true man   in the middle may attempt to take data out of an association and fool   the sender into thinking that the data was actually received by the   peer.  In generic TLS for SCTP (and/or TCP), this is not possible.   This means that the removal of a message may become hidden from the   sender or receiver.  Another vulnerability of using PR-SCTP with DTLS   is that someone could inject SCTP control information to shut down   the SCTP association, effectively generating a loss of IPFIX Messages   if those are buffered outside of the SCTP association.  In the   future, techniques such as [dtls-for-sctp] could be used to overcome   these vulnerabilities.   When using DTLS over SCTP, the Exporting Process MUST ensure that   each IPFIX Message is sent over the same SCTP stream that would be   used when sending the same IPFIX Message directly over SCTP.  Note   that DTLS may send its own control messages on stream 0 with full   reliability; however, this will not interfere with the processing of   stream 0 IPFIX Messages at the Collecting Process, because DTLS   consumes its own control messages before passing IPFIX Messages up to   the application layer.Claise, et al.              Standards Track                    [Page 47]

RFC 5101              IPFIX Protocol Specification          January 200811.2.  Usage   The IPFIX Exporting Process initiates the communication to the IPFIX   Collecting Process, and acts as a TLS or DTLS client according to   [RFC4346] and [RFC4347], while the IPFIX Collecting Process acts as a   TLS or DTLS server.  The DTLS client opens a secure connection on the   SCTP port 4740 of the DTLS server if SCTP or PR-SCTP is selected as   the transport protocol.  The TLS client opens a secure connection on   the TCP port 4740 of the TLS server if TCP is selected as the   transport protocol.  The DTLS client opens a secure connection on the   UDP port 4740 of the DTLS server if UDP is selected as the transport   protocol.11.3.  Authentication   IPFIX Exporting Processes and IPFIX Collecting Processes are   identified by the fully qualified domain name of the interface on   which IPFIX Messages are sent or received, for purposes of X.509   client and server certificates as in [RFC3280].   To prevent man-in-the-middle attacks from impostor Exporting or   Collecting Processes, the acceptance of data from an unauthorized   Exporting Process, or the export of data to an unauthorized   Collecting Process, strong mutual authentication via asymmetric keys   MUST be used for both TLS and DTLS.  Each of the IPFIX Exporting and   Collecting Processes MUST verify the identity of its peer against its   authorized certificates, and MUST verify that the peer's certificate   matches its fully qualified domain name, or, in the case of SCTP, the   fully qualified domain name of one of its endpoints.   The fully qualified domain name used to identify an IPFIX Collecting   Process or Exporting Process may be stored either in a subjectAltName   extension of type dNSName, or in the most specific Common Name field   of the Subject field of the X.509 certificate.  If both are present,   the subjectAltName extension is given preference.   Internationalized domain names (IDN) in either the subjectAltName   extension of type dNSName or the most specific Common Name field of   the Subject field of the X.509 certificate MUST be encoded using   Punycode [RFC3492] as described inSection 4 of [RFC3490],   "Conversion Operations".11.4.  Protection against DoS Attacks   An attacker may mount a denial-of-service (DoS) attack against an   IPFIX collection system either directly, by sending large amounts of   traffic to a Collecting Process, or indirectly, by generating large   amounts of traffic to be measured by a Metering Process.Claise, et al.              Standards Track                    [Page 48]

RFC 5101              IPFIX Protocol Specification          January 2008   Direct denial-of-service attacks can also involve state exhaustion,   whether at the transport layer (e.g., by creating a large number of   pending connections), or within the IPFIX Collecting Process itself   (e.g., by sending Flow Records pending Template or scope information,   a large amount of Options Template Records, etc.).   SCTP mandates a cookie-exchange mechanism designed to defend against   SCTP state exhaustion denial-of-service attacks.  Similarly, TCP   provides the "SYN cookie" mechanism to mitigate state exhaustion; SYN   cookies SHOULD be used by any Collecting Process accepting TCP   connections.  DTLS also provides cookie exchange to protect against   DTLS server state exhaustion.   The reader should note that there is no way to prevent fake IPFIX   Message processing (and state creation) for UDP & SCTP communication.   The use of TLS and DTLS can obviously prevent the creation of fake   states, but they are themselves prone to state exhaustion attacks.   Therefore, Collector rate limiting SHOULD be used to protect TLS &   DTLS (like limiting the number of new TLS or DTLS session per second   to a sensible number).   IPFIX state exhaustion attacks can be mitigated by limiting the rate   at which new connections or associations will be opened by the   Collecting Process, the rate at which IPFIX Messages will be accepted   by the Collecting Process, and adaptively limiting the amount of   state kept, particularly records waiting on Templates.  These rate   and state limits MAY be provided by a Collecting Process; if   provided, the limits SHOULD be user configurable.   Additionally, an IPFIX Collecting Process can eliminate the risk of   state exhaustion attacks from untrusted nodes by requiring TLS or   DTLS mutual authentication, causing the Collecting Process to accept   IPFIX Messages only from trusted sources.   With respect to indirect denial of service, the behavior of IPFIX   under overload conditions depends on the transport protocol in use.   For IPFIX over TCP, TCP congestion control would cause the flow of   IPFIX Messages to back off and eventually stall, blinding the IPFIX   system.  PR-SCTP improves upon this situation somewhat, as some IPFIX   Messages would continue to be received by the Collecting Process due   to the avoidance of head-of-line blocking by SCTP's multiple streams   and partial reliability features, possibly affording some visibility   of the attack.  The situation is similar with UDP, as some datagrams   may continue to be received at the Collecting Process, effectively   applying sampling to the IPFIX Message stream, implying that some   forensics may be left.Claise, et al.              Standards Track                    [Page 49]

RFC 5101              IPFIX Protocol Specification          January 2008   To minimize IPFIX Message loss under overload conditions, some   mechanism for service differentiation could be used to prioritize   IPFIX traffic over other traffic on the same link.  Alternatively,   IPFIX Messages can be transported over a dedicated network.  In this   case, care must be taken to ensure that the dedicated network can   handle the expected peak IPFIX Message traffic.11.5.  When DTLS or TLS Is Not an Option   The use of DTLS or TLS might not be possible in some cases due to   performance issues or other operational concerns.   Without TLS or DTLS mutual authentication, IPFIX Exporting Processes   and Collecting Processes can fall back on using IP source addresses   to authenticate their peers.  A policy of allocating Exporting   Process and Collecting Process IP addresses from specified address   ranges, and using ingress filtering to prevent spoofing, can improve   the usefulness of this approach.  Again, completely segregating IPFIX   traffic on a dedicated network, where possible, can improve security   even further.  In any case, the use of open Collecting Processes   (those that will accept IPFIX Messages from any Exporting Process   regardless of IP address or identity) is discouraged.   Modern TCP and SCTP implementations are resistant to blind insertion   attacks (see [RFC1948], [RFC4960]); however, UDP offers no such   protection.  For this reason, IPFIX Message traffic transported via   UDP and not secured via DTLS SHOULD be protected via segregation to a   dedicated network.11.6.  Logging an IPFIX Attack   IPFIX Collecting Processes MUST detect potential IPFIX Message   insertion or loss conditions by tracking the IPFIX Sequence Number,   and SHOULD provide a logging mechanism for reporting out-of-sequence   messages.  Note that an attacker may be able to exploit the handling   of out-of-sequence messages at the Collecting Process, so care should   be taken in handling these conditions.  For example, a Collecting   Process that simply resets the expected Sequence Number upon receipt   of a later Sequence Number could be temporarily blinded by deliberate   injection of later Sequence Numbers.   IPFIX Exporting and Collecting Processes SHOULD log any connection   attempt that fails due to authentication failure, whether due to   being presented an unauthorized or mismatched certificate during TLS   or DTLS mutual authentication, or due to a connection attempt from an   unauthorized IP address when TLS or DTLS is not in use.Claise, et al.              Standards Track                    [Page 50]

RFC 5101              IPFIX Protocol Specification          January 2008   IPFIX Exporting and Collecting Processes SHOULD detect and log any   SCTP association reset or TCP connection reset.11.7.  Securing the Collector   The security of the Collector and its implementation is important to   achieve overall security.  However, it is outside the scope of this   document.12.  IANA Considerations   IPFIX Messages use two fields with assigned values.  These are the   IPFIX Version Number, indicating which version of the IPFIX Protocol   was used to export an IPFIX Message, and the IPFIX Set ID, indicating   the type for each set of information within an IPFIX Message.   The IPFIX Version Number value of 10 is reserved for the IPFIX   protocol specified in this document.  Set ID values of 0 and 1 are   not used for historical reasons [RFC3954].  The Set ID value of 2 is   reserved for the Template Set.  The Set ID value of 3 is reserved for   the Option Template Set.  All other Set ID values from 4 to 255 are   reserved for future use.  Set ID values above 255 are used for Data   Sets.   New assignments in either IPFIX Version Number or IPFIX Set ID   assignments require a Standards Action [RFC2434], i.e., they are to   be made via Standards Track RFCs approved by the IESG.Claise, et al.              Standards Track                    [Page 51]

RFC 5101              IPFIX Protocol Specification          January 2008Appendix A.  IPFIX Encoding Examples   This appendix, which is a not a normative reference, contains IPFIX   encoding examples.   Let's consider the example of an IPFIX Message composed of a Template   Set, a Data Set (which contains three Data Records), an Options   Template Set and a Data Set (which contains 2 Data Records related to   the previous Options Template Record).   IPFIX Message:   +--------+------------------------------------------. . .   |        | +--------------+ +------------------+   |Message | | Template     | | Data             |   | Header | | Set          | | Set              |   . . .   |        | | (1 Template) | | (3 Data Records) |   |        | +--------------+ +------------------+   +--------+------------------------------------------. . .        . . .-------------------------------------------+              +------------------+ +------------------+ |              | Options          | | Data             | |       . . .  | Template Set     | | Set              | |              | (1 Template)     | | (2 Data Records) | |              +------------------+ +------------------+ |        . . .-------------------------------------------+A.1.  Message Header Example   The Message Header is composed of:    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 = 0x000a          |         Length = 152          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          Export Time                          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                        Sequence Number                        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                     Observation Domain ID                     |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+Claise, et al.              Standards Track                    [Page 52]

RFC 5101              IPFIX Protocol Specification          January 2008A.2.  Template Set ExamplesA.2.1.  Template Set Using IETF-Specified Information Elements   We want to report the following Information Elements:   - The IPv4 source IP address: sourceIPv4Address in [RFC5102],     with a length of 4 octets   - The IPv4 destination IP address: destinationIPv4Address in     [RFC5102], with a length of 4 octets   - The next-hop IP address (IPv4): ipNextHopIPv4Address in     [RFC5102], with a length of 4 octets   - The number of packets of the Flow: inPacketDeltaCount in     [RFC5102], with a length of 4 octets   - The number of octets of the Flow: inOctetDeltaCount in     [RFC5102], with a length of 4 octets   Therefore, the Template Set will be composed of the following:    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 = 2            |      Length = 28 octets       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       Template ID 256         |       Field Count = 5         |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|    sourceIPv4Address = 8    |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0| destinationIPv4Address = 12 |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|  ipNextHopIPv4Address = 15  |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|   inPacketDeltaCount = 2    |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|   inOctetDeltaCount =  1    |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+A.2.2.  Template Set Using Enterprise-Specific Information Elements   We want to report the following Information Elements:   - The IPv4 source IP address: sourceIPv4Address in [RFC5102], with a     length of 4 octetsClaise, et al.              Standards Track                    [Page 53]

RFC 5101              IPFIX Protocol Specification          January 2008   - The IPv4 destination IP address: destinationIPv4Address in     [RFC5102], with a length of 4 octets   - An enterprise-specific Information Element representing proprietary     information, with a type of 15 and a length of 4   - The number of packets of the Flow: inPacketDeltaCount in [RFC5102],     with a length of 4 octets   - The number of octets of the Flow: inOctetDeltaCount in [RFC5102],     with a length of 4 octets   Therefore, the Template Set will be composed of the following:    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 = 2            |      Length = 32 octets       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       Template ID 257         |       Field Count = 5         |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|    sourceIPv4Address = 8    |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0| destinationIPv4Address = 12 |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |1| Information Element Id. = 15|       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                       Enterprise number                       |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|   inPacketDeltaCount = 2    |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |0|   inOctetDeltaCount = 1     |       Field Length = 4        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+Claise, et al.              Standards Track                    [Page 54]

RFC 5101              IPFIX Protocol Specification          January 2008A.3.  Data Set Example   In this example, we report the following three Flow Records:   Src IP addr. | Dst IP addr.  | Next Hop addr. | Packet | Octets                |               |                | Number | Number   ------------------------------------------------------------------   192.0.2.12   | 192.0.2.254   | 192.0.2.1      | 5009   | 5344385   192.0.2.27   | 192.0.2.23    | 192.0.2.2      | 748    | 388934   192.0.2.56   | 192.0.2.65    | 192.0.2.3      | 5      | 6534    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 = 256         |          Length = 64          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.12                           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.254                          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.1                            |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                             5009                              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                            5344385                            |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.27                           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.23                           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.2                            |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                              748                              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                             388934                            |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.56                           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.65                           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                          192.0.2.3                            |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                               5                               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                              6534                             |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   Note that padding is not necessary in this example.Claise, et al.              Standards Track                    [Page 55]

RFC 5101              IPFIX Protocol Specification          January 2008A.4.  Options Template Set ExamplesA.4.1.  Options Template Set Using IETF-Specified Information Elements   Per line card (the router being composed of two line cards), we want   to report the following Information Elements:   - Total number of IPFIX Messages: exportedPacketCount [RFC5102], with     a length of 2 octets   - Total number of exported Flows: exportedFlowCount [RFC5102], with a     length of 2 octets   The line card, which is represented by the lineCardId Information   Element [RFC5102], is used as the Scope Field.   Therefore, the Options Template Set will be:    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 = 3            |          Length = 24          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       Template ID 258         |        Field Count = 3        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |     Scope Field Count = 1     |0|     lineCardId = 141        |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |   Scope 1 Field Length = 4    |0|  exportedPacketCount = 41   |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       Field Length = 2        |0|   exportedFlowCount = 42    |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       Field Length = 2        |           Padding             |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+A.4.2.  Options Template Set Using Enterprise-Specific Information        Elements   Per line card (the router being composed of two line cards), we want   to report the following Information Elements:      - Total number of IPFIX Messages: exportedPacketCount [RFC5102],        with a length of 2 octets      - An enterprise-specific number of exported Flows, with a type of        42 and a length of 4 octets   The line card, which is represented by the lineCardId Information   Element [RFC5102], is used as the Scope Field.Claise, et al.              Standards Track                    [Page 56]

RFC 5101              IPFIX Protocol Specification          January 2008   The format of the Options Template Set is as follows:     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 = 3            |          Length = 28          |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |       Template ID 259         |        Field Count = 3        |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |     Scope Field Count = 1     |0|     lineCardId = 141        |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |   Scope 1 Field Length = 4    |0|  exportedPacketCount = 41   |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |       Field Length = 2        |1|Information Element Id. = 42 |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |       Field Length = 4        |       Enterprise number     ...    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    ...      Enterprise number      |           Padding             |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+A.4.3.  Options Template Set Using an Enterprise-Specific Scope   In this example, we want to export the same information as in the   example in Section A.4.1:      - Total number of IPFIX Messages: exportedPacketCount [RFC5102],        with a length of 2 octets      - Total number of exported Flows: exportedFlowCount [RFC5102],        with a length of 2 octets   But this time, the information pertains to a proprietary scope,   identified by enterprise-specific Information Element number 123.Claise, et al.              Standards Track                    [Page 57]

RFC 5101              IPFIX Protocol Specification          January 2008   The format of the Options Template Set is now as follows:     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 = 3            |          Length = 28          |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |       Template ID 260         |        Field Count = 3        |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |     Scope Field Count = 1     |1|Scope 1 Infor. El. Id. = 123 |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |    Scope 1 Field Length = 4   |       Enterprise Number      ...    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   ...       Enterprise Number      |0|  exportedPacketCount = 41   |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |       Field Length = 2        |0|   exportedFlowCount = 42    |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |       Field Length = 2        |           Padding             |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+A.4.4.  Data Set Using an Enterprise-Specific Scope   In this example, we report the following two Data Records:   Line Card ID               | IPFIX Message  | Exported Flow Records   -------------------------------------------------------------------   Line Card 1 (lineCardId=1) | 345            | 10201   Line Card 2 (lineCardId=2) | 690            | 20402    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 = 260             |         Length = 20           |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                               1                               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |             345               |            10201              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                               2                               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |             690               |            20402              |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+Claise, et al.              Standards Track                    [Page 58]

RFC 5101              IPFIX Protocol Specification          January 2008A.5.  Variable-Length Information Element ExamplesA.5.1.  Example of Variable-Length Information Element with Length        Inferior to 255 Octets    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   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       5       |          5 octet Information Element          |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                               |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+A.5.2.  Example of Variable-Length Information Element with Length 255        to 65535 Octets    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      |             1000              |    IE ...     |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                1000 octet Information Element                 |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   :                              ...                              :   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                             ... IE            |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ReferencesNormative References   [RFC1305]       Mills, D., "Network Time Protocol (Version 3)                   Specification, Implementation and Analysis",RFC1305, March 1992.   [RFC2119]       Bradner, S., "Key words for use in RFCs to Indicate                   Requirement Levels",BCP 14,RFC 2119, March 1997.   [RFC2434]       Narten, T. and H. Alvestrand, "Guidelines for Writing                   an IANA Considerations Section in RFCs",BCP 26,RFC2434, October 1998.   [RFC3280]       Housley, R., Polk, W., Ford, W., and D. Solo,                   "Internet X.509 Public Key Infrastructure Certificate                   and Certificate Revocation List (CRL) Profile",RFC3280, April 2002.Claise, et al.              Standards Track                    [Page 59]

RFC 5101              IPFIX Protocol Specification          January 2008   [RFC3436]       Jungmaier, A., Rescorla, E., and M. Tuexen,                   "Transport Layer Security over Stream Control                   Transmission Protocol",RFC 3436, December 2002.   [RFC3758]       Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.                   Conrad, "Stream Control Transmission Protocol (SCTP)                   Partial Reliability Extension",RFC 3758, May 2004.   [RFC4346]       Dierks, T. and E. Rescorla, "The Transport Layer                   Security (TLS) Protocol Version 1.1",RFC 4346, April                   2006.   [RFC4347]       Rescorla, E. and N. Modadugu, "Datagram Transport                   Layer Security",RFC 4347, April 2006.   [RFC3490]       Faltstrom, P., Hoffman, P., and A. Costello,                   "Internationalizing Domain Names in Applications                   (IDNA)",RFC 3490, March 2003.   [RFC3492]       Costello, A., "Punycode: A Bootstring encoding of                   Unicode for Internationalized Domain Names in                   Applications (IDNA)",RFC 3492, March 2003.   [RFC4960]       Stewart, R., Ed., "Stream Control Transmission                   Protocol",RFC 4960, September 2007.   [RFC5102]       Quittek, J., Bryant S., Claise, B., Aitken, P., and                   J. Meyer, "Information Model for IP Flow Information                   Export",RFC 5102, January 2008.   [TCP]           Postel, J., "Transmission Control Protocol", STD 7,RFC 793, September 1981.   [UDP]           Postel, J., "User Datagram Protocol", STD 6,RFC 768,                   August 1980.Informative References   [IPFIX-ARCH]    Sadasivan, G., Brownlee, N., Claise, B., and J.                   Quittek, "Architecture Model for IP Flow Information                   Export", Work in Progress, September 2006.   [IPFIX-AS]      Zseby, T., Boschi, E., Brownlee, N., and B. Claise,                   "IPFIX Applicability", Work in Progress, June 2007.   [PEN]           IANA Private Enterprise Numbers registryhttp://www.iana.org/assignments/enterprise-numbers.Claise, et al.              Standards Track                    [Page 60]

RFC 5101              IPFIX Protocol Specification          January 2008   [RFC1948]       Bellovin, S., "Defending Against Sequence Number                   Attacks",RFC 1948, May 1996.   [RFC2579]       McCloghrie, K., Perkins, D., and J. Schoenwaelder,                   "Textual Conventions for SMIv2", STD 58,RFC 2579,                   April 1999.   [RFC3917]       Quittek, J., Zseby, T., Claise, B., and S. Zander,                   "Requirements for IP Flow Information Export                   (IPFIX)",RFC 3917, October 2004.   [RFC3550]       Schulzrinne, H., Casner, S., Frederick, R., and V.                   Jacobson, "RTP: A Transport Protocol for Real-Time                   Applications", STD 64,RFC 3550, July 2003.   [RFC3954]       Claise, B., Ed., "Cisco Systems NetFlow Services                   Export Version 9",RFC 3954, October 2004.   [IEEE.754.1985] Institute of Electrical and Electronics Engineers,                   "Standard for Binary Floating-Point Arithmetic", IEEE                   Standard 754, August 1985.   [dtls-for-sctp] Tuexen, M. and E. Rescola, "Datagram Transport Layer                   Security for Stream Control Transmission Protocol",                   Work in Progress, November 2007.Acknowledgments   We would like to thank the following persons: Ganesh Sadasivan for   his significant contribution during the initial phases of the   protocol specification; Juergen Quittek for the coordination job   within IPFIX and PSAMP; Nevil Brownlee, Dave Plonka, Paul Aitken, and   Andrew Johnson for the thorough reviews; Randall Stewart and Peter   Lei for their SCTP expertise and contributions; Martin Djernaes for   the first essay on the SCTP section; Michael Behringer and Eric   Vyncke for their advice and knowledge in security; Michael Tuexen for   his help regarding the DTLS section; Elisa Boschi for her   contribution regarding the improvement of SCTP sections; Mark   Fullmer, Sebastian Zander, Jeff Meyer, Maurizio Molina, Carter   Bullard, Tal Givoly, Lutz Mark, David Moore, Robert Lowe, Paul   Calato, and many more, for the technical reviews and feedback.Claise, et al.              Standards Track                    [Page 61]

RFC 5101              IPFIX Protocol Specification          January 2008Authors' Addresses   Benoit Claise   Cisco Systems   De Kleetlaan 6a b1   1831 Diegem   Belgium   Phone: +32 2 704 5622   EMail: bclaise@cisco.com   Stewart Bryant   Cisco Systems, Inc.   250, Longwater,   Green Park,   Reading, RG2 6GB,   United Kingdom   Phone: +44 (0)20 8824-8828   EMail: stbryant@cisco.com   Simon Leinen   SWITCH   Werdstrasse 2   P.O. Box   CH-8021 Zurich   Switzerland   Phone: +41 44 268 1536   EMail: simon.leinen@switch.ch   Thomas Dietz   NEC Europe Ltd.   NEC Laboratories Europe   Network Research Division   Kurfuersten-Anlage 36   69115 Heidelberg   Germany   Phone: +49 6221 4342-128   EMail: Thomas.Dietz@nw.neclab.eu   Brian H. Trammell   CERT Network Situational Awareness   Software Engineering Institute   4500 Fifth Avenue   Pittsburgh, PA 15213   United States   Phone: +1 412 268 9748   EMail: bht@cert.orgClaise, et al.              Standards Track                    [Page 62]

RFC 5101              IPFIX Protocol Specification          January 2008Full Copyright Statement   Copyright (C) The IETF Trust (2008).   This document is subject to the rights, licenses and restrictions   contained inBCP 78, and except as set forth therein, the authors   retain all their rights.   This document and the information contained herein are provided on an   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Intellectual Property   The IETF takes no position regarding the validity or scope of any   Intellectual Property Rights or other rights that might be claimed to   pertain to the implementation or use of the technology described in   this document or the extent to which any license under such rights   might or might not be available; nor does it represent that it has   made any independent effort to identify any such rights.  Information   on the procedures with respect to rights in RFC documents can be   found inBCP 78 andBCP 79.   Copies of IPR disclosures made to the IETF Secretariat and any   assurances of licenses to be made available, or the result of an   attempt made to obtain a general license or permission for the use of   such proprietary rights by implementers or users of this   specification can be obtained from the IETF on-line IPR repository athttp://www.ietf.org/ipr.   The IETF invites any interested party to bring to its attention any   copyrights, patents or patent applications, or other proprietary   rights that may cover technology that may be required to implement   this standard.  Please address the information to the IETF at   ietf-ipr@ietf.org.Claise, et al.              Standards Track                    [Page 63]