IPFIX working group Internet Draft EDITORS: B. Claise draft-ietf-ipfix-protocol-02.txt Cisco Systems Expires: July 2004 Mark Fullmer OARnet Paul Calato Riverstone Networks Reinaldo Penno Nortel Networks January 2003 IPFIX Protocol Specifications Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsolete by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document discusses the IPFIX protocol that provides network administrators with access to IP flows information. This document focuses on how IPFIX flow record data, options record data and control information is carried (via a congestion-aware transport protocol) from IPFIX exporting process to IPFIX collecting process. Conventions used in this document Claise, et. al Standard Track [Page 1] IPFIX Protocol Specifications January 2004 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. Table of Contents 1. Points of Discussion.........................................3 1.1 Open Issues................................................3 1.2 Action Items...............................................5 2. Introduction.................................................5 2.1 Overview...................................................5 3. Terminology..................................................6 3.1 Terminology Summary Table.................................10 4. The Metering Process........................................11 4.1 Flow Expiration...........................................11 5. Transport Protocol..........................................12 5.1 TCP.......................................................12 5.2 STCP......................................................12 5.2.1 Congestion Avoidance...................................12 5.2.2 Reliability............................................12 5.2.3 Exporting Process......................................13 5.2.3.1 MTU size..............................................13 5.2.3.2 Source ID.............................................13 5.2.3.3 Association...........................................13 5.2.3.4 Stream................................................14 5.2.3.5 Template..............................................14 5.2.4 Collecting Process.....................................14 5.2.5 SCTP Partially Reliable................................15 6. Failover....................................................16 6.1 Simple Failover based on the transport protocol...........16 6.2 Something else?...........................................16 7. Message Layout..............................................16 8. IPFIX Message Format........................................18 8.1 Header Format.............................................18 8.2 Field Type Format.........................................19 8.3 Template FlowSet Format...................................20 8.3.1 IETF Exclusive Template FlowSet Format.................20 8.3.2 Vendor Specified Template FlowSet Format...............22 8.4 Data FlowSet Format.......................................24 9. Options.....................................................25 9.1 Options Template FlowSet Format...........................25 9.1.1 IETF Exclusive Options Template FlowSet Format.........25 9.1.2 Vendor Specified Options Template FlowSet Format.......27 9.2 Options Data Record Format................................29 9.3 Specific IPFIX Options Templates..........................30 9.3.1 The Metering Process Statistics Option Template........31 10. Export Packet UNIX Secs Computation and Flow Record Times..31 10.1 Microsecond Precision....................................31 10.2 Millisecond Precision....................................32 Claise, et. al Standard Track [Page 2] IPFIX Protocol Specifications January 2004 10.3 Nanosecond Precision.....................................33 10.4 Multiple Precisions......................................33 11. Linkage with the Information Model.........................33 11.1 Boolean..................................................33 11.2 Byte.....................................................34 11.3 UnsignedByte.............................................34 11.4 Short....................................................34 11.5 Reduced Size Encoding of Integral Types..................34 12. Variable Length Data Type..................................35 13. Template Management........................................36 14. The Collecting Process's Side..............................37 15. Security Considerations....................................39 16. IANA Considerations........................................43 17. Examples...................................................43 17.1 Message Header Example...................................44 17.2 Template FlowSet Example.................................44 17.3 Data FlowSet Example.....................................45 17.4 Options Template FlowSet Example.........................46 17.5 Data FlowSet with Options Data Records Example...........46 18. References.................................................47 18.1 Normative References.....................................47 18.2 Informative References...................................47 19. Acknowledgments............................................48 1. Points of Discussion 1.1 Open Issues This section covers the open issues, still to be resolved/updated in this draft: - The proposal on the table is to send a IPFIX Sync (this would be an Options Data Records) message periodically (periodicity is configurable), with the following information (aside the standard IPFix header) * Number of flow records sent (for each template?) * Packets and bytes sent (for each template?) Question: Per observation domain? Question: Do we need a specific FlowSet ID? - Template don't need lifetimes with connection oriented protocol. We guess this is the consensus from the Working Group. The section 11 "Template Management" will have to updated according to the transport protocol. For example, the point 2 of the section 11 "Template Management" Claise, et. al Standard Track [Page 3] IPFIX Protocol Specifications January 2004 - No periodic retransmission of templates is needed, with a reliable transport protocol. Remark: the template management will vary with TCP, SCTP, etcą Must have both sections updated: transport updated and template management sections (BTW, this is the same for the failover section). - Export ID (ie IP address of exporter) sent to the collector. This can be done once with an options template. - Metering process stats: for example packets / flows dropped at the metering process due to resource exhaustion, etcą This can be done with an options template. - Error recovery, for example what to do if a collector receives a message it can't decode. Per protocol issue, ie TCP reset the session because it's a stream protocol and can't recover. - If we tackle reliability a state diagram is needed. - Talk a little bit about extensibility, for example make some decisions now about the reserved template ID's 2-254 for future work. - Abstract. This document "specifies" + expand it - Must develop a Security Section - IANA considerations section to be expanded. - Potentially some discrepancies between data types, field type and Information Element terminology. - Need an example with the Vendor Specified Information Element - Review the requirements draft to see what we miss, once it's an I- RFC - Templates identified by FLowset IDs, 0 => 'template,' 1 => 'options template,' [2,255] => reserved, [256 ) => 'data template.' Need to specify this (and mechanism for defined other 'well-known' values in IANA Considerations section (not yet written). - Section 5.2.3.3, Association: What happens if the Exporter gets no response from any Collector? I think we should specify a (not-too- aggressive) retry algorithm. - ęętransport protocolĘĘ section to be updated. Note: each transport protocol (TCP/SCTP) should have at least the following subsections: Reliability, Failover, Template Management Bert Wijnen is currently working on this issue: http:// ipfix.doit .wisc.edu/archive/2336.html - Nevil comment: Section 10: Variable Length Data Type: Surely this really belongs in the Info Model I-D? The Info Model I-D defines the 'string' data type as "finite length string of valid characters .." It needs to say something about whether the length is fixed or Claise, et. al Standard Track [Page 4] IPFIX Protocol Specifications January 2004 variable. Seems to me that making all strings be variable-length would be fine. - IANI considerations section to be updated: have a look at RFC 2434, which sets out guidelines for IANA Considerations. Also, searching the RFCs for 'IANA Considerations' brings up quite a few RFCs to look at as models. - Flow Sampling. This is mentioned in both the Requirements I-D and the AS I-D. We need to decide how it should be covered in the IPFIX drafts. - Section 11.4 must be completed with type used in [IPFIX-INFO] - Protocol Extensions must be discussed in the draft - Need a consensus/discussion on section 9.3.1 "The Metering Process Statistics Option Template". The [IPFIX-INFO] needs also the appropriate data types 1.2 Action Items This section covers the action items for this draft - 4.1 Flow Expiration -> add the notion of integers versus counters, after minneapolis WG consensus - Use of MUST/SHOULD vs must/should: this is a Standards Track draft, there are lots of places I think RFC 2119 (upper case) would be more appropriate, starting with section 5.2.3.1. (Most of these would be simple 'editing' changes). - 9.2 Options Data Record Format The Options Data Records are sent in Data FlowSets, on a regular basis, but not with every Flow Data Record. How frequently these Options Data Records are exported is configurable. See the Templates Management" section for more details. -> not the right section + expand - check the examples with the information model - I received the comment to number all the figures 2. Introduction 2.1 Overview The IPFIX protocol provides network administrators with access to IP flows information. The architecture for the export of measured IP flow information out of an IPFIX exporting process to a collecting processing is defined in [IPFIX-ARCH], per the requirements defined in [IPFIX-REQ]. [IPFIX-PROTO] specifies how IPFIX flow record data, options record data and control information is carried via a Claise, et. al Standard Track [Page 5] IPFIX Protocol Specifications January 2004 congestion-aware transport protocol from IPFIX exporting process to IPFIX collecting process. IPFIX has a formal description of IPFIX information elements (fields), their name, type and additional semantic information, as specified in [IPFIX-INFO]. 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. 3. Terminology The definitions of IP Traffic Flow, Metering Process, Exporting Process and Collecting Process are the definitions as found in the IPFIX requirement document [IPFIX-REQ]. Note nevertheless that, even if the Observation Point definition has been also been completely copied over from the IPFIX requirement document [IPFIX- REQ], this definition has been expanded. The terminology summary table in Section 3.1 gives a quick overview of the relationships between some of the different terms defined. Observation Point The Observation Point is a location in the network where IP packets can be observed. Examples are 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. An Observation Domain is associated with every Observation Point. Note that one Observation Point may be a superset of several other Observation Points. For example one Observation Point can be an entire line card. This would be the superset of the individual Observation Points at the line card's interfaces. Observation Domain The set of Observation Points, which is the largest aggregatable set of Flow information at the Metering Process is termed an Observation Domain. Each Observation Domain presents itself as a unique ID to the Collecting Process for identifying the IPFIX Messages it generates. For example, a router line card composed of several interfaces with each interface being an Observation Point. Claise, et. al Standard Track [Page 6] IPFIX Protocol Specifications January 2004 IP Traffic Flow or Flow There are several definitions of the term 'flow' being used by the Internet community. Within this document we use the following one: 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 field (e.g. destination IP address), transport header field (e.g. destination port number), or application header field (e.g. RTP header fields [RFC1889]) 2. one or more characteristics of the packet itself (e.g. number of MPLS labels, etc...) 3. one or more of fields derived from packet treatment (e.g. next hop IP address, the output interface, etc...) A packet is defined to belong 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 with a specific sequence number. Please note that the Flow definition does not necessarily match a general application-level end-to-end stream. However, an application may derive properties of application-level streams by processing measured Flow data. Also, please note that although packet properties may depend on application headers, there is no requirement defined in this document related to application headers. Flow Record A Flow Record provides information about an IP Traffic Flow observed at an Observation Point. Metering Process The Metering Process generates Flow Records. Input to the process are packet headers observed at an Observation Point and packet Claise, et. al Standard Track [Page 7] IPFIX Protocol Specifications January 2004 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. The sampling function and the classifying function may be applied more than once with different parameters. Figure 1 shows the sequence in which the functions are applied. Sampling is not illustrated in the figure, it may be applied before any other function. packet header capturing | timestamping | v +----->+ | | | classifying | | +------+ | maintaining Flow Records | v Figure 1: Functions of the Metering Process 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. Collecting Process Claise, et. al Standard Track [Page 8] IPFIX Protocol Specifications January 2004 The Collecting Process receives Flow Records from one or more Exporting Processes. The Collecting Process might store received Flow Records or further process them, but these actions are out of the scope of this document. IPFIX Message An IPFIX Message is a message originating at the Exporting Process that carries the Flow Records of this Exporting Process and whose destination is the Collecting Process. 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 Flow Data Record. Flow Data Record A Flow Data Record is a data record that contains values of the Flow parameters corresponding to a Template Record. In this document, the Flow Data Record is also referred to as Flow Record. Options Template Record An Options Template Record defines the structure and interpretation of fields in an Options Data Record, including defining how to scope the applicability of the Options Data Record. Options Data Record The Options Data Record is a data record that contains values and scope information of the Flow measurement parameters, corresponding to an Options Template Record. FlowSet Claise, et. al Standard Track [Page 9] IPFIX Protocol Specifications January 2004 FlowSet is a generic term for a collection of records that have a similar structure. In an IPFIX Message, one or more FlowSets follow the Message Header. There are three different types of FlowSets: Template FlowSet, Options Template FlowSet, and Data FlowSet. Template FlowSet A Template FlowSet is a collection of one or more Template Records that have been grouped together in an IPFIX Message. Options Template FlowSet An Options Template FlowSet is a collection of one or more Options Template Records that have been grouped together in an IPFIX Message. Data FlowSet A Data FlowSet is one or more records, of the same type, that are grouped together in an IPFIX Message. Each record is either a Flow Data Record or an Options Data Record previously defined by a Template Record or an Options Template Record. Information Element An Information Element is a protocol and encoding independent description of an attribute which may appear in an IPFIX flow record. The IPFIX information model [IPFIX-INFO] 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 determine the valid encoding mechanisms for use in IPFIX. 3.1 Terminology Summary Table FlowSet Template Record Data Record +----------------------------------------------------------------+ | | | Flow Data Record(s) | | Data FlowSet | / | or | | | | Options Data Record(s) | +----------------------------------------------------------------+ | Template FlowSet | Template Record(s) | / | Claise, et. al Standard Track [Page 10] IPFIX Protocol Specifications January 2004 +----------------------------------------------------------------+ | Options Template | Options Template | / | | FlowSet | Record(s) | | +----------------------------------------------------------------+ A Data FlowSet is composed of an Options Data Record(s) or Flow Data Record(s). No Template Record is included. A Template Record defines the Flow Data Record, and an Options Template Record defines the Options Data Record. A Template FlowSet is composed of Template Record(s). No Flow or Options Data Record is included. An Options Template FlowSet is composed of Options Template Record(s). No Flow or Options Data Record is included. 4. The Metering Process The description of the Metering Process (for example, sampled or not, aggregation or not), which is the way in which Flows are created from the observed IP packets, is beyond the scope of this document. Nevertheless, some aspects of the Metering Process have some influences on the IPFIX protocol 4.1 Flow Expiration A Flow is considered to be inactive if no packets belonging to the Flow have been observed at the Observation Point for a given timeout. If any packet is seen within the timeout, the flow is considered an active Flow. A Flow can be exported under the following conditions: 1. If the Metering Process can detect the end of a Flow. For example, if the FIN or RST bit is detected in a TCP [TCP] connection, the Flow Record is exported. 2. If the Flow has been inactive for a certain period of time. This inactivity timeout SHOULD be configurable at the Metering Process, with a minimum value of 0 for an immediate expiration. 3. For long-lasting Flows, the Exporting Process SHOULD export the Flow Records on a regular basis. This timeout SHOULD be configurable at the Metering Process. Claise, et. al Standard Track [Page 11] IPFIX Protocol Specifications January 2004 4. If the Metering Process experiences internal constraints, a Flow MAY be forced to expire prematurely; for example, counters wrapping or low memory. 5. Transport Protocol The IPFIX Protocol Specifications have been designed to be transport protocol independent. It can operate over congestion-aware protocols such as TCP [TCP] or SCTP [RFC2960]. Note that the Exporter can export to multiple Collecting Processes, using independent transport protocols. 5.1 TCP To be completed. TCP [TCP] 5.2 STCP This section describes how IPFIX can be transported over SCTP [RFC2960] using traditional reliable mode. IPFIX can also be transported over the partial reliable or unreliable mode [PR-SCTP]. These last 2 modes will be briefly discussed, while waiting for [PR-SCTP] to become a standard. 5.2.1 Congestion Avoidance The SCTP transport protocol provides the required level of congestion avoidance by design. 5.2.2 Reliability The SCTP transport protocol is by default reliable, but has the capability to operate in unreliable and partially reliable modes [PR-SCTP]. Using reliable SCTP streams (referred to hereafter as "streams") for the IPFIX export is not in itself a guarantee that all records are delivered. If there is congestion on the link from the exporter to the collector, or if a significant Claise, et. al Standard Track [Page 12] IPFIX Protocol Specifications January 2004 amount of retransmissions are needed, the send queues on the Exporting Process may fill up. In that case it's up to the Exporting Process to decide what to do. It may either halt export (buffer the data until there is space in the send queues again) or discard IPFIX Messages away instead of inserting them into the send queue. If any data is not inserted into the send queues, the sequence numbers used for export must reflect the loss of data. 5.2.3 Exporting Process 5.2.3.1 MTU size Each IPFIX Message should be equal to or less than the local MTU in size. When an IPFIX Message is transmitted over a network with an MTU smaller than the local MTU, IP fragmentation may be used. 5.2.3.2 Source ID The IPFIX Message must contain a Message Header, which includes a source id (SID). The SID indicates from which Observation Domain the data is being exported, and should be kept unique for each such Observation Domain. If a Metering Process consists of a single Observation Domain, a single SID value must be used for all IPFIX Messages. The Exporting Process will typically open one association to the collector, but more are possible, in which one or more streams can be used. The Exporting Process has the choice of transmitting parts of the export data in separate streams or all data in one stream. If a Metering Process consists of multiple Observation Domains, one SID value for each Observation Domain must be used. The Exporting Process will typically open one association, but more are possible, in which at least one stream per Observation Domain is used. The Exporting Process has the choice of using more than one stream per Observation Domain, but data from multiple Observation Domains should not be transmitted over the same stream. 5.2.3.3 Association The Exporting Process may create one or more associations Claise, et. al Standard Track [Page 13] IPFIX Protocol Specifications January 2004 (connection "bundle" in SCTP terminology) to the Collecting Process. The Collecting Process may not initiate the connection. Inside each association one or more streams may be requested by the Exporting Process. If the Collecting Process can not support the requested number of streams, it may choose to refuse the connection and the Exporting Process should try to reduce, if possible, the number of streams needed to perform the export. 5.2.3.4 Stream An Observation Domain must use at least one stream, but may use multiple streams, to export data records. The Observation Domain must use the same SID value for all streams used. An Exporting Process must not transmit messages with different SID values in one stream, the Collecting Process should however verify that the SID values are the expected values. 5.2.3.5 Template Since the SCTP association is connection oriented the available Template Records must be transmitted from each Observation Domain to the Collecting Process immediately after the association is established. As a minimum the Template Records must be transmitted immediately after they start to exist on the Metering Process and should preferably be transmitted before any data, using the new Template Record, have been transmitted. The Collecting Process should however accept data without a Template Record. When using a reliable mode for Template Record export, or if the exporter knows that the IPFIX Message containing the templates was positively acknowledged by the SCTP layer, it is not necessary to periodically export the Template Records. 5.2.4 Collecting Process 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. If the Collecting Process doesn't support the number of streams inside the association, the Claise, et. al Standard Track [Page 14] IPFIX Protocol Specifications January 2004 Collecting Process must refuse the connection and continue listen for a new request. When data is received from an association, the Collecting Process must correlate data, with the same SID (Source ID) value, from multiple streams into one export Flow from an Observation Domain. This allows the Observation Domain to use separate streams for different types of information. The Collecting Process should verify that the received IPFIX Messages inside one stream does not have differing SID values. The Exporting Process must not transmit messages inside one stream with multiple SID values. The correlated Flow Records are then treated like a normal export Flow. 5.2.5 SCTP Partially Reliable This mode will not be discussed any further until [PR-SCTP] becomes a standard, even if this mode offers a few advantages: freedom to use SCTP as a reliable, single stream transport, as well as multiple streams with different properties, for example in terms of reliability, carrying different data types dependant on their importance for the system. Unreliable or partial reliability may be chosen for one or more streams inside an association. Unreliable transport may be preferred where large amount of data is to be exported and keeping send queues is either an unnecessary overhead or impractical. Partial reliability may be chosen where a small amount of queuing is possible. Naturally it is better to send templates over a reliable stream and send the data on an unreliable (or partial reliable) stream. When an exporter handles data with different properties it might even be preferable to send them over different streams according to those properties. Example: an Exporting Process can use two streams per Observation Domain. A reliable stream could be used for exporting templates, to reduce the likelihood of loss and to remove the need for blind retransmissions, and a partial or unreliable stream for data, to avoid buffering of large amounts of data. Claise, et. al Standard Track [Page 15] IPFIX Protocol Specifications January 2004 6. Failover When to fail over? How to fail back? How to ensure stability of the failover mechanism (prevent oscillations)? Does the exporter open connections to all the potential collectors and keep them primed with template info? 6.1 Simple Failover based on the transport protocol In case the transport protocol is connection oriented. So in case of TCP [TCP] or SCTP [RFC2960]. To be completed. 6.2 Something else? Potentially based on some application level ACK from the exporter? 7. Message Layout An IPFIX Message consists of a Message Header followed by one or more FlowSets. The FlowSets can be any of the possible three types: Template, Data, or Options Template. IPFIX Message: +--------+-------------------------------------------+ | | +----------+ +---------+ +----------+ | |Message | | Template | | Data | | Options | | | Header | | FlowSet | | FlowSet | | Template | ... | | | | | | | | FlowSet | | | | +----------+ +---------+ +----------+ | +--------+-------------------------------------------+ A FlowSet ID is used to distinguish the different types of FlowSets. FlowSet IDs lower than 256 are reserved for special FlowSets, such as the Template FlowSet (ID 0) and the Options Template FlowSet (ID 1). The Data FlowSets have a FlowSet ID greater than 255. The format of the Template, Data, and Options Template FlowSets will be discussed later in this document. The Exporter MUST code all fields of the different FlowSets in network byte order (big-endian). Claise, et. al Standard Track [Page 16] IPFIX Protocol Specifications January 2004 Following are some examples of IPFIX Messages: 1. An IPFIX Message consisting of interleaved Template, Data, and Options Template FlowSets-A newly created Template is exported as soon as possible. So if there is already an IPFIX Message with a Data FlowSet that is being prepared for export, the Template and Option FlowSets are also interleaved with this information, subject to availability of space. IPFIX Message: +--------+--------------------------------------------------------+ | | +----------+ +---------+ +-----------+ +---------+ | |Message | | Template | | Data | | Options | | Data | | | Header | | FlowSet | | FlowSet | ... | Template | | FlowSet | | | | | | | | | FlowSet | | | | | | +----------+ +---------+ +-----------+ +---------+ | +--------+--------------------------------------------------------+ 2. An IPFIX Message consisting entirely of Data FlowSets-After the appropriate Template Records have been defined and transmitted to the Collecting Process, the majority of IPFIX Messages consists solely of Data FlowSets. IPFIX Message: +--------+----------------------------------------------+ | | +---------+ +---------+ +---------+ | |Message | | Data | ... | Data | ... | Data | | | Header | | FlowSet | ... | FlowSet | ... | FlowSet | | | | +---------+ +---------+ +---------+ | +--------+----------------------------------------------+ 3. An IPFIX Message consisting entirely of Template and Options Template FlowSets-The Exporter MAY transmit a message containing Template and Options Template FlowSets periodically to help ensure that the Collecting Process has the correct Template Records and Options Template Records when the corresponding Flow Data records are received. IPFIX Message: +--------+-------------------------------------------------+ | | +----------+ +----------+ +----------+ | |Message | | Template | | Template | | Options | | | Header | | FlowSet | ... | FlowSet | ... | Template | | Claise, et. al Standard Track [Page 17] IPFIX Protocol Specifications January 2004 | | | | | | | FlowSet | | | | +----------+ +----------+ +----------+ | +--------+-------------------------------------------------+ 8. IPFIX Message Format 8.1 Header Format 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sysUpTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | UNIX Secs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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. Length Total Length is the length of the IPFIX message, measured in octets, including message Header and FlowSet(s). sysUpTime Time in milliseconds since this device was first booted. UNIX Secs Time in seconds since 0000 UTC 1970, at which the Export Packet leaves the Exporter. Sequence Number Incremental sequence counter of all IPFIX Messages sent from the current Observation Domain by the Exporting Process. This value MUST be cumulative, and SHOULD be used by the Claise, et. al Standard Track [Page 18] IPFIX Protocol Specifications January 2004 Collector to identify whether any IPFIX Messages have been missed. Source ID A 32-bit value that identifies the Exporter Process Observation Domain. Collecting Process SHOULD use the combination of the source IP address and the Source ID field to separate different export streams originating from the same Exporting Process. 8.2 Field Type Format This section describes the Field Type format for both IETF specified Information Elements [IPFIX-INFO] and Vendor Specified Information Elements. Vendors need the ability to define proprietary Information Elements, because, for example, they are delivering pre-standards product, or the Information Element is in some way commercially sensitive. The Field Ids used to identify Information Elements are divided into two non-overlapping ranges: the IETF specified range and the vendor specified range. This partitioning of the identifiers into two ranges allows the Collecting Process to discriminate between an IETF specified Information Element and a Vendor Specified Information Element. The vendor specified range is shared by all vendors, and thus needs an accompanying vendor identifier to uniquely identify it. The format of an IETF defined Field Type is shown in Fig A. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Fig A: IETF defined Field Type Where: Field Type A numeric value that represents the type of the field. Refer Claise, et. al Standard Track [Page 19] IPFIX Protocol Specifications January 2004 to [IPFIX-INFO]. Field Length The length of the corresponding Field Type, in bytes. Refer to [IPFIX-INFO]. The format of the Vendor Specified Field Type is shown in Fig B. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Fig B: Vendor Specified Field Type Where: Field Type A numeric value that represents the type of the field. Refer to [IPFIX-INFO]. Field Length The length of the corresponding Field Type, in bytes. Refer to [IPFIX-INFO]. Enterprise Number IANA enterprise number [PEN] of the authority defining the field type in this template record. 8.3 Template FlowSet Format One of the essential elements in the IPFIX format is the Template FlowSet. Templates greatly enhance the flexibility of the Flow Record format because they allow the Collecting Process to process Flow Records without necessarily knowing the interpretation of all the data in the Flow Record. 8.3.1 IETF Exclusive Template FlowSet Format Claise, et. al Standard Track [Page 20] IPFIX Protocol Specifications January 2004 The IETF exclusive Template FlowSet MAY be used when the template contains only IETF defined Information Elements. This format is provided for backwards compatibility [NETFLOW9]. The format of the IETF exclusive Template FlowSet is shown in Figure C. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 0 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 1 | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 1 | Field Length 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 2 | Field Length 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type N | Field Length N | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 2 | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 1 | Field Length 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 2 | Field Length 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type M | Field Length M | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID K | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure C: IETF Exclusive Template FlowSet Format Field Descriptions FlowSet ID FlowSet ID value of 0 is reserved for the Template FlowSet. Claise, et. al Standard Track [Page 21] IPFIX Protocol Specifications January 2004 Length Total length of this FlowSet. Because an individual Template FlowSet MAY contain multiple Template Records, the Length value MUST be used to determine the position of the next FlowSet record, which could be any type of FlowSet. Length is the sum of the lengths of the FlowSet ID, the Length itself, and all Template Records within this FlowSet. Template ID Each of the newly generated Template Records is given a unique Template ID. This uniqueness is local to the Observation Domain that generated the Template ID. Template IDs 0-255 are reserved for Template FlowSets, Options FlowSets, and other reserved FlowSets yet to be created. Template IDs of Data FlowSets are numbered from 256 to 65535. Field Count Number of fields in this Template Record. Because a Template FlowSet usually contains multiple Template Records, this field allows the Collecting Process to determine the end of the current Template Record and the start of the next. Field Type A numeric value that represents the type of the field. Refer to [IPFIX-INFO]. Field Length The length of the corresponding Field Type, in bytes. Refer to [IPFIX-INFO]. 8.3.2 Vendor Specified Template FlowSet Format A vendor specified Template FlowSet MUST be used when the template contains one or more Vendor Specified Information Elements. A vendor specified template MAY exclusively contain IETF defined Field Types. A vendor specified template MAY contain Vendor Specified Information Elements from multiple vendors. The format of the Vendor Specified Template FlowSet is shown in Figure D. 0 1 2 3 Claise, et. al Standard Track [Page 22] IPFIX Protocol Specifications January 2004 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 2 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 1 | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 1 | Field Length 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number 1.1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 2 | Field Length 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type N | Field Length N | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number 1.N | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 2 | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 1 | Field Length 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type 2 | Field Length 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number 2.2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Type M | Field Length M | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number 2.M | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure D: Vendor Specified Template Flowset The definition of the fields in the Vendor Specified Template FlowSet is identical to those described IETF exclusive Template FlowSet Format Field Descriptions except: FlowSet ID FlowSet ID value of 2 is reserved for the Vendor Specified Template FlowSet Claise, et. al Standard Track [Page 23] IPFIX Protocol Specifications January 2004 Enterprise Number IANA enterprise number [PEN] of the authority defining the field type in this template record. 8.4 Data FlowSet Format The format of the Data FlowSet 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet 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 | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Data FlowSet Field Descriptions FlowSet ID = Template ID Each Data FlowSet is associated with a FlowSet ID. The FlowSet ID maps to a (previously generated) Template ID. The Collecting Process MUST use the FlowSet ID to find the corresponding Template Record and decode the Flow Records from the FlowSet. Length The length of this FlowSet. Length is the sum total of lengths of FlowSet ID, Length itself, all Flow Records within this FlowSet, and the padding bytes, if any. Record N - Field Value M Claise, et. al Standard Track [Page 24] IPFIX Protocol Specifications January 2004 The remainder of the Data FlowSet is a collection of Flow Data Record(s), each containing a set of field types and values. The Type and Length of the fields have been previously defined in the Template Record referenced by the FlowSet ID or Template ID. Padding The Exporting Process SHOULD insert some padding bytes so that the subsequent FlowSet starts at a 4-byte aligned boundary. It is important to note that the Length field includes the padding bits. Interpretation of the Data FlowSet format can be done only if the Template FlowSet corresponding to the Template ID is available at the Collecting Process. 9. Options 9.1 Options Template FlowSet Format The Options Template Record (and its corresponding Options Data Record) is used to supply information about the Metering Process configuration or Metering Process specific data, rather than supplying information about IP Flows. For example, the Options Template FlowSet can report the sample rate of a specific interface, if sampling is supported, along with the sampling method used. 9.1.1 IETF Exclusive Options Template FlowSet Format The IETF exclusive Options Template FlowSet Format MAY be used when the template contains only IETF defined options. This format is provided for backwards compatibility [NETFLOW9]. The format of the IETF exclusive Options Template FlowSet Format is shown in Figure E. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 1 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID | Option Scope Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Claise, et. al Standard Track [Page 25] IPFIX Protocol Specifications January 2004 | Option Length | Scope 1 Field Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope 1 Field Length | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope N Field Length | Option 1 Field Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option 1 Field Length | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option M Field Length | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure E: IETF Exclusive Options Template FlowSet The IETF Exclusive Options Template FlowSet Field Definitions are as follows: FlowSet ID = 1 A FlowSet ID value of 1 is reserved for the Options Template. Length Total length of this FlowSet. Each Options Template FlowSet MAY contain multiple Options Template Records. Thus, the Length value MUST be used to determine the position of the next FlowSet record, which could be either a Template FlowSet or Data FlowSet. Length is the sum total of lengths of FlowSet ID, the Length itself, and all Options Template Records within this FlowSet Template ID. Template ID Template ID of this Options Template. This value is greater than 255. Option Scope Length The length in bytes of any Scope fields definition contained in the Options Template Record (The use of "Scope" is described below). Option Length The length (in bytes) of any options field definitions contained in this Options Template Record. Claise, et. al Standard Track [Page 26] IPFIX Protocol Specifications January 2004 Scope 1 Field Type The relevant portion of the Exporting Process/Metering Process to which the Options Template Record refers. Currently defined values are: 1 System 2 Interface 3 Line Card 4 Cache 5 Template For example, the Metering Process can be implemented on a per-interface basis, so if the Options Template Record were reporting on how the Metering Process is configured, the Scope for the report would be 2 (interface). The associated interface ID would then be carried in the associated Options Data FlowSet. The Scope can be limited further by listing multiple scopes that all must match at the same time. Note that the Scope fields always precede the Option fields. Scope 1 Field Length The length (in bytes) of the Scope field, as it would appear in an Options Data Record. Option 1 Field Type A numeric value that represents the type of field that would appear in the Options Template Record. Refer to [IPFIX- INFO]. Option 1 Field Length The length (in bytes) of the Option Field. Padding The Exporting Process SHOULD insert some padding bytes so that the subsequent FlowSet starts at a 4-byte aligned boundary. It is important to note that the Length field includes the padding bits. 9.1.2 Vendor Specified Options Template FlowSet Format A vendor specified Options Template MUST be used when the template contains one or more vendor specified options. A vendor specified Options Template MAY exclusively contain IETF defined Field Types. A vendor specified template MAY contain Vendor Specified Information Elements from multiple vendors. Claise, et. al Standard Track [Page 27] IPFIX Protocol Specifications January 2004 The format of the Vendor Specified Options Template FlowSet is shown in Figure E. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 3 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID | Option Scope Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Length | Reserved must be zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope 1 Field Type | Scope 1 Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope N Field Type | Scope N Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope N Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option 1 Field Type | Option 1 Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option 1 Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option N Field Type | Option N Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure E: Vendor Specified Option Template FlowSet The definition of the fields in the vendor specified Options Template FlowSet is identical to those described IETF Exclusive Options Template FlowSet Format Field Descriptions except: FlowSet ID = 3 A FlowSet ID value of 3 is reserved for a VI Qualified Options Template. Scope N Enterprise Number IANA enterprise number [PEN] of the authority defining Scope N. Claise, et. al Standard Track [Page 28] IPFIX Protocol Specifications January 2004 Option N Enterprise Number IANA enterprise number [PEN] of the authority defining the Option N field type. 9.2 Options Data Record Format The Options Data Records are sent in Data FlowSets, on a regular basis, but not with every Flow Data Record. How frequently these Options Data Records are exported is configurable. See the Templates Management" section for more details. The format of the Data FlowSet containing Options Data Records 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = Template ID | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Record 1 - Scope 1 Value |Record 1 - Option Field 1 Value| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Record 1 - Option Field 2 Value| ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Record 2 - Scope 1 Value |Record 2 - Option Field 1 Value| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Record 2 - Option Field 2 Value| ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Record 3 - Scope 1 Value |Record 3 - Option Field 1 Value| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Record 3 - Option Field 2 Value| ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Options Data Records of the Data FlowSet Field Descriptions FlowSet ID = Template ID A FlowSet ID precedes each group of Options Data Records within a Data FlowSet. The FlowSet ID maps to a previously generated Template ID corresponding to this Options Template Record. The Collecting Process MUST use the FlowSet ID to Claise, et. al Standard Track [Page 29] IPFIX Protocol Specifications January 2004 map the appropriate type and length to any field values that follow. Length The length of this FlowSet. Length is the sum of the lengths of the FlowSet ID, Length itself, all the Options Data Records within this FlowSet, and the padding bytes, if any. Record N - Option Field M Value The remainder of the Data FlowSet is a collection of Flow Records, each containing a set of scope and field values. The type and length of the fields were previously defined in the Options Template Record referenced by the FlowSet ID or Template ID. Padding The Exporting Process SHOULD insert some padding bytes so that the subsequent FlowSet starts at a 4-byte aligned boundary. It is important to note that the Length field includes the padding bits. The Data FlowSet format can be interpreted only if the Options Template FlowSet corresponding to the Template ID is available at the Collecting Process. 9.3 Specific IPFIX Options Templates Some specific Options Templates and Options Templates Records are necessary to provide extra information about the Flow Records and about the Metering Process. The ipfixOption [IPFIX-INFO], always included in these specific Options Templates, defines the type of information sent in the Option Template / Option Template Record pair. For example, if the ipfixOption [IPFIX-INFO] value is METER_STATS, then the Option Template will specify information about the Metering Process statistics. The ipfixOption [IPFIX-INFO] MUST always be the first Data Type in the Option Template so that the Collector could quickly determine whether or not a specific Option Template is described. And if the ipfixOption [IPFIX-INFO] is present, which specific Option Template type it defines. Claise, et. al Standard Track [Page 30] IPFIX Protocol Specifications January 2004 The minimum set of Data Types is always specified in these Specific IPFIX Options Templates. Nevertheless, extra Data Types MAY be used in these specific Options Templates. 9.3.1 The Metering Process Statistics Option Template The Metering Process Statistics Option Template defines the Metering Process Statistics with the export of the following Data Types [IPFIX- INFO]: ipfixOption The value MUST be METER_STATS observationDomain Source ID lostFlows flows not exported due to resource starvation(**) lostFlowsPacket Packets in the lost flows (**) lostFlowsBytes Bytes in the lost flows (**) droppedPacketCount Packets dropped by Metering Process at the Observation Point droppedByteCount Bytes dropped by Metering Process at the Observation Domain time; When this record was generated The minimum set of Data Type in the Metering Process Statistics Option Template is: ipfixOption, observationDomain, lostFlows, time 10. Export Packet UNIX Secs Computation and Flow Record Times 10.1 Microsecond Precision For a Data FlowSet with Flow Records requiring microsecond precision, the Export Packet UNIX Secs field MUST be calculated so that each Flow Records flowStartUsec [IPFIX-INFO] and flowEndUsec [IPFIX-INFO] would contain a 32 bit signed microsecond offset from the UNIX Secs base timestamp. Hereafter some pseudo code to calculate the UNIX Secs in one pass, which would return an absolute duration of 35 minutes for all Flow Records contained in the Data FlowSet. Flow Records MUST be exported in different Export Packet if the absolute duration can not fit in those 35 minutes. // pseudo code for microsecond offset in IPFIX encoded Flow Records. // struct flow{ Claise, et. al Standard Track [Page 31] IPFIX Protocol Specifications January 2004 uint32 tv_sec; uint32 tv_usec; uint32 numbytes; ... // other information elements... }; struct flow flowtable [MAX_TABLE_SIZE]; int lastflowindex = -1; writeflows() { if (lastflowindex < 0) return; // simply take the second field from the first available flow // and make this the base time for this collection of flows. uint32 base_sec = flowtable[0].tv_sec; writeheaderToSocket(base_sec); // put 32-bit second value in header for (int i=0; i<=lastflowindex; i++){ int32 offset = (flowtable[i].tv_sec - base_sec) * 1000000 + flowtable[i].tv_usec; writeint32ToSocket(offset); // put the 32-bit time offset in the record. // write other information elements... } } A two pass approach calculation for the optimum (center) UNIX Secs base timestamp would allow an absolute duration of 71 minutes for all Flow Records contained in the Data FlowSet. The two pass approach MAY be used. The UNIX Secs base timestamp calculation requires that at the Export Packet exporting time the Exporting Process MUST run down the list of Flow Records in the Data FlowSet message and adjust the Flow start and Flow end timestamps. 10.2 Millisecond Precision For a Data FlowSet with Flow Records requiring a millisecond precision, the same principles as in section 9.1 "Microsecond Precision" will be used. The only difference will be that the Flow start and the Flow end SHOULD now be represented respectively by the flowStartMsec [IPFIX- INFO] and flowEndMsec [IPFIX-INFO]. As a consequence of the Claise, et. al Standard Track [Page 32] IPFIX Protocol Specifications January 2004 millisecond precision, the absolute duration of all Flow Records is now of about 49 days. The Export Header UNIX Secs base time SHOULD be calculated with the algorithm described in the Section 9.1 "Microsecond Precision". In order to reduce the load on the Exporter, the Export Header UNIX Secs MAY be the time in seconds since 0000 UTC 1970 at which the Export Packet leaves the Exporter and not the calculated optimum value anymore as described in section 9.1 "Microsecond Precision". Alternatively, for a Data FlowSet with Flow Records requiring a millisecond precision, the microsecond mechanism as described in section 9.1 MAY be used as such. The Flow Record MAY use the flowStartUsec [IPFIX-INFO] and flowEndUsec [IPFIX-INFO] rounded at a millisecond precision. 10.3 Nanosecond Precision For a Data FlowSet with Flow Records requiring a nanosecond precision, all Flow Records will contain Flow start flowStartNsec [IPFIX-INFO] and flowEndNsec [IPFIX-INFO]. The Export Header UNIX Secs will be of no use on the Collector side in this case as the flowStartNsec [IPFIX-INFO] and flowEndNsec [IPFIX-INFO] both have a nanosecond precision already. Both flowStartNsec [IPFIX-INFO] and flowEndNsec [IPFIX-INFO] use the NTP time format which is represented as a 64-bit value which contains a 32-bit specification of seconds since 1900 and a 32-bit "fraction" field. Refer to the NTP specification, RFC1305, section 3.1 "Data Formats". 10.4 Multiple Precisions When Flow Records requiring different precisions must be exported, the Exporting Process SHOULD split the Flow Records in different Data FlowSet according to the precision: millisecond, microsecond or nanosecond. 11. Linkage with the Information Model The information model associates each IPFIX Data Type with a well defined type, such as hexBinary, long, unsignedInt, etc. This document defines how fields of a given type are encoded. 11.1 Boolean Claise, et. al Standard Track [Page 33] IPFIX Protocol Specifications January 2004 A boolean field shall be encoded in a single byte with the value of 0 indicating false and any other value indicating true. 11.2 Byte A byte value shall be encoded as a single byte representing a value between -128 and 127. The value is represented in two's complement notation. 11.3 UnsignedByte An unsigned byte value shall be encoded as a single byte representing a value between 0 and 255. 11.4 Short A short is a 16-bit datum that encodes an integer in the range [- 32768,32767]. The short is represented in two's complement notation. The most and least significant bytes are 0 and 1, respectively EDITOR NOTE: this section 11 must be completed with types used in [IPFIX-INFO], taking the descriptions from XDR RFC1832, sections 3.x 11.5 Reduced Size Encoding of Integral Types Information Elements containing integral types in the information model MAY be encoded using fewer bytes than those implied by their type in the information model definition [IPFIX-INFO], based on the assumption that the smaller type 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 model Data Types definition [IPFIX-INFO] will always define the maximum encoding size for each Data Type. For instance the information model [IPFIX-INFO] defines byteCount as an unsignedLong 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 unsignedInt. For example, a core router would require an unsignedLong byteCount while an unsignedInt might be sufficient for Claise, et. al Standard Track [Page 34] IPFIX Protocol Specifications January 2004 an access router. This behavior is indicated by the exporter by specifying a type size smaller than that associated with the assigned type of the field. In the example above the exporter would place a length of 4 vs. 8 in the template. Reduced sizing MAY only be applied to the following integral types: short, unsignedShort, int, unsignedInt, long, unsignedLong. In each case the downcasting must be to a smaller integral type which MUST have the same signed vs. unsigned properties. Specifically unsignedLong may be downcast to unsignedInt, unsignedShort or unsignedByte. A long may be downcast to an int a short or a byte. The other downcasts follow the same pattern. 12. Variable Length Data Type The IPFIX template mechanism is optimized for fixed length Information Elements [IPFIX-INFO]. Where an Information Element has a variable length the following mechanism is used to carry the length information. In the Template FlowSet the 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 itself. In most cases the length of the Information Element will be less than 256 bytes. The following length encoding mechanism optimizes the overhead of carrying the Information Element length in this majority case. If the length of the Information Element is less than 255 bytes, the length is carried in the first byte of the Information Element. This is shown on Figure A. 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 | Claise, et. al Standard Track [Page 35] IPFIX Protocol Specifications January 2004 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure A: Variable Length Information Element (length < 255 bytes) If the length of the Information Element is greater or equal than 256 bytes, the first byte of the Information Element is 255, and the length is carried in the second and third bytes of the Information Element. This is shown in Figure B. 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 (256 to 65535) | IE | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... continuing as needed | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure B: Variable Length Information Element (length 256 to 65535) bytes 13. Template Management Flow Data records that correspond to a Template Record MAY appear in the same and/or subsequent IPFIX Messages. The Template Record is not necessarily carried in every IPFIX Message. As such, the Collecting Process MUST store the Template Record to interpret the corresponding Flow Data Records that are received in subsequent data messages. A Collecting Process that receives IPFIX Messages from several Observation Domains from the same Exporter MUST be aware that the uniqueness of the Template ID is not guaranteed across Observation Domains. The Template IDs must remain constant for the life of the Metering Process and the Exporting Process. If the Exporting Process or the Metering Process restarts for any reason, all information about Templates will be lost and new Template IDs will be created. Template IDs are thus not guaranteed to be consistent across an Exporting Process or Metering Process restart. A newly created Template record is assigned an unused Template ID from the Exporter. If the template configuration is changed, the Claise, et. al Standard Track [Page 36] IPFIX Protocol Specifications January 2004 current Template ID is abandoned and SHOULD NOT be reused until the Metering Process. If a Collecting Process should receive a new definition for an already existing Template ID, it MUST discard the previous template definition and use the new one. If a configured Template Record on the Exporting Process is deleted, and re-configured with exactly the same parameters, the same Template ID COULD be reused. The Exporting Process sends the Template FlowSet and Options Template FlowSet under the following conditions: 1. After a Metering Process restarts, the Exporting Process MUST NOT send any Data FlowSet without sending the corresponding Template FlowSet and the required Options Template FlowSet in a previous message or including it in the same IPFIX Message. It MAY transmit the Template FlowSet and Options Template FlowSet, without any Data FlowSets, in advance to help ensure that the Collector will have the correct Template Record before receiving the first Flow or Options Data Record. 2. In the event of configuration changes, the Exporting Process SHOULD send the new template definitions at an accelerated rate. In such a case, it MAY 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. 3. On a regular basis, the Exporting Process MUST send all the Template Records and Options Template Records to refresh the Collecting Process. Template IDs have a limited lifetime at the Collecting Process and MUST be periodically refreshed. Two approaches are taken to make sure that Templates get refreshed at the Collecting Process: * Every N number of IPFIX Messages. * On a time basis, so every N number of minutes. Both options MUST be configurable by the user on the Exporting Porcess. When one of these expiry conditions is met, the Exporting Process MUST send the Template FlowSet and Options Template. 14. The Collecting Process's Side Claise, et. al Standard Track [Page 37] IPFIX Protocol Specifications January 2004 The Collecting Process receives Template Records from the Exporting Process, normally before receiving Flow Data Records (or Options Data Records). The Flow Data Records (or Options Data Records) can then be decoded and stored locally on the devices. If the Template Records have not been received at the time Flow Data Records (or Options Data Records) are received, the Collecting Process SHOULD store the Flow Data Records (or Options Data Records) and decode them after the Template Records are received. A Collecting Process device MUST NOT assume that the Data FlowSet and the associated Template FlowSet (or Options Template FlowSet) are exported in the same IPFIX Message. The Collecting Process MUST NOT assume that one and only one Template FlowSet is present in an IPFIX Message. The life of a template at the Collecting Process is limited to a fixed refresh timeout. Templates not refreshed from the Exporting Process within the timeout are expired at the Collecting Process. The Collecting Process MUST NOT attempt to decode the Flow or Options Data Records with an expired Template. At any given time the Collecting Process SHOULD maintain the following for all the current Template Records and Options Template Records: Note that the Observation Domain is identified by the Source ID field from the IPFIX Message. Template IDs are unique per Exporting Process and per Observation Domain. If the Collecting Process receives a new Template Record (for example, in the case of an Exporter restart) it MUST immediately override the existing Template Record. The Collecting Process MUST note the Field ID of any Information Element that it does not understand and MAY discard the Information Element from the Flow Record. The Collecting Process MUST note the size and position of any Vendor Specified Information Element that it does not understand and discard the Information Element from the Flow Record. The Collector MUST accept padding in the Data FlowSet and Options Template FlowSet, which means for the Flow Data Records, the Options Data Records and the Template Records. Claise, et. al Standard Track [Page 38] IPFIX Protocol Specifications January 2004 Refer to the terminology summary table in Section 3.1. The IPFIX protocol has a sequence number field in the Export Header which increases with each message. A Collector may detect out of sequence, dropped, or duplicate messages by tracking the sequence number. A collector SHOULD provide a logging mechanism for tracking out of sequence messages. Such out of sequence messages may be due to congestion on the network link between the Exporter and Collector, Collector resource exhaustion where it can not process the IPFIX messages at their arrival rate, Exporter resource exhaustion where it can not transmit messages at their creation rate, out of order packet reception, duplicate packet reception, an Exporting Process reset, or an attacker injecting false messages. 15. Security Considerations Because IPFIX can be used to collect billing information and network forensics, confusing or blinding IPFIX must be seen as a prime objective during a sophisticated network attack. If an attacker is in a position to inject false messages into an IPFIX message stream this will allow them to send forged flow records, options, or templates. Forged templates may impair the Collectors ability to process any further Flow Records. Forged Flow Records would have a direct effect on the application using the Flows, for example a billing system may generate incorrect billing information. Forged options may be able to alter the meaning of flow records, for example if the sample rate is changed. The IPFIX messages themselves may contain information of value to an attacker, and thus care must be taken to confine their visibility to authorized users. The IPFIX protocol runs over IP and hence the messages sent to the collector by the exporter may be secured using IPsec. However this does not address all of the security issues in an IPsec deployment. 15.1 IPsec Profile To secure messages between the Exporter and the Collector an IPFIX implementation MAY use IPsec. To ensure interworking between Exporters and Collectors from different vendors, the following IPsec profile MUST be supported. This profile is derived from [USEIPSEC]. Claise, et. al Standard Track [Page 39] IPFIX Protocol Specifications January 2004 15.1.1 Selectors IPFIX runs between manually configured pairs of hosts on the following transport ports (TBD). The appropriate selector would be Exporter Collector pairs and port number Note that if the Exporter is a router a non-interface ("loopback") address should be used. 15.1.2 Mode IPsec MUST be run in transport mode. The Authentication Header (AH) [RFC2402] MUST be used if authentication is required. The Security Protocol (ESP) [RFC2406] must be used if the is a threat to the IPFIX message content, or if it is confidential. Normally in situations where the ESP was required the AH would also be required. If ESP is used, the sender's IP address MUST be checked against the IP address asserted in the key management exchange. The AH MUST be supported by an IPFIX implementation of IPsec. 15.1.3 Key Management In many networks, manual key management will be sufficient, and reduces the complexity of the Exporter, albeit at a cost of greater configuration complexity. Manual key management MUST be supported. If a replay attack is considered likely, an automated key management the IKE key management system SHOULD be used. 15.1.4 Security Policy Connections should be accepted only from the designated peer. 15.1.5 Authentication Given the number of IPFIX capable Exporters are likely to be deployed by a large ISPs, there will be circumstances where shared key mechanisms are not adequate. Where an automated key management system is used, certificate-based IKE SHOULD be supported. Claise, et. al Standard Track [Page 40] IPFIX Protocol Specifications January 2004 15.1.6 Availability It is accepted that IPsec will not be universally available in IPFIX Exporters, and that where it is available, there may be issues of throughput, which may itself raise security issues. In such circumstances the other security measures described in this draft provide some threat mitigation. 15.2 Network Architecture Ideally messages from the IPFIX Exporter to the IPFIX Collector should travel over a dedicated network such as a dedicated point to point link. In all cases, useful protection is gained by allocating Exporter and Collector IP addresses from ranges that are excluded from use for user traffic. By sending the IPFIX messages over a dedicated network, message IPFIX message loss induced by user traffic congestion is minimized. However an attacker may trigger the generation of excessive IPFIX messages, and to avoid information loss during such an attack the IPFIX network must be adequately sized. The use of a dedicated network also prevents the IPFIX messages from being inspected by an attacker. 15.3 When IPsec is not an option When IPsec is not an option, perhaps due to performance issues, but some level of protection against an insertion attack is required, it is recommended that a 64 bit cookie [L2TPv3] be included as a mandatory element within all messages. Without IPsec the IPFIX Collector has no means to authenticate an exporter other than the Exporters Source IP address. Where large numbers of exporters, proxies and collectors are used in a network, it may be tempting for the administrator to not impose source IP address restrictions, this leaves the Collector open to reception of invalid flows. The use proxies using an open collector is therefore to be deprecated. 15.4 Transport Issues Some IPFIX security issues are dependent on the transport. For example with UDP unsolicited messages may be received and not detected, with a modern implementation of TCP with good ISN randomization [XXX-REFERENCE] or SCTP these types of attacks are much more difficult without an attacker with access to snoop the packet flow [XXX-SCTP-BLIND-SPOOFING-REFERENCE]. Randomization of the IPFIX sequence number might mitigate the in case of UDP problem. However in all these cases, the sequence number space is relatively small giving Claise, et. al Standard Track [Page 41] IPFIX Protocol Specifications January 2004 limited protection. An attacker may take advantage of the pathology of the transport protocol or its common implementations to mount and attack on IPFIX. This might be either as an assault on IPFIX in its own right or intended to blind IPFIX to prevent the recording of network forensics as part of another attack. Under conditions where the attacker saturated IPFIX, for example by initiating the generating enormous numbers of short lived flows, the behavior of the IPFIX transport would determine the amount of evidence that was recorded. If the transport protocol were UDP, then under network overload conditions IPFIX would reduce to some sort of sampling. This means that the attacked could never be quite sure that IPFIX was blinded, and that they may hence be leaving forensics. If the transport were TCP, then the flow to the collector would back off due to congestion discard and eventually stall blinding the IPFIX system. An attack could then proceed without further observation. The extent and duration of the blindness would depend on the detail of the TCP implementation. SCTP-PR will have a different pathology under such a saturation attack. Stale data at the head of the queue will get flushed giving some visibility of the attack. Whilst the use of a congestion aware transport protocol is highly desirable to protect the network from overload by excessive IPFIX traffic, this is exactly wrong behavior when IPFIX is being to diagnose a DoS attack, or an attack proceeding under cover of a DoS attack. Under these circumstance you want the IPFIX transport needs to be congestion neutral (as is UDP), or congestion aggressive. 15.5 Logging an IPFIX Attack The IPFIX protocol has a sequence number field in the Export Header which increases with each message. A Collector may detect out of sequence, dropped, or duplicate messages by tracking the sequence number. A Collector SHOULD provide a logging mechanism for tracking out of sequence messages. Such out of sequence messages may be due to congestion on the network link between the Exporter and Collector, Collector resource exhaustion where it can not process the IPFIX messages at their arrival rate, Exporter resource exhaustion where it can not transmit messages at their creation rate, out of order packet reception, duplicate packet reception, an Exporting Process reset, or an attacker injecting false messages. Claise, et. al Standard Track [Page 42] IPFIX Protocol Specifications January 2004 Note that an attacker may be able to exploit the behavior of the Collector when it receives an out of sequence message. For example a Collector that simply reset the expected sequence number upon receipt of a later message would easily be temporarily blinded by deliberately injecting messages with a much larger sequence number. 16. IANA Considerations IANA will need to set up a registry of Flowset IDs, field types, scope and option codepoints. In compiling the registry of field types IANA must set asside a range value for vendor use. It is proposed that the range <0..32767> be administered by IANA for IETF defined IEs, and that the range <32768..65535> be allocated for private use by vendors. Similarly the scope and option codepoints need to be split between IANA administered and private ranges. 17. Examples Let's consider the example of an IPFIX Message composed of a Template FlowSet, a Data FlowSet (which contains three Flow Data Records), an Options Template FlowSet and a Data FlowSet (which contains 2 Options Data Records). IPFIX Message: +--------+---------------------------------------------. . . | | +--------------+ +-----------------------+ |Message | | Template | | Data | | Header | | FlowSet | | FlowSet | . . . | | | (1 Template) | | (3 Flow Data Records) | | | +--------------+ +-----------------------+ +--------+---------------------------------------------. . . . . .+-------------------------------------------------+ +------------------+ +--------------------------+ | | Options | | Data | | . . .| Template FlowSet | | FlowSet | | | (1 Template) | | (2 Options Data Records) | | +------------------+ +--------------------------+ | . . .--------------------------------------------------+ Claise, et. al Standard Track [Page 43] IPFIX Protocol Specifications January 2004 17.1 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 = 0x0009 | Length = 152 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | UNIX Secs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 17.2 Template FlowSet Example We want to report the following Field Types: - The source IP address (IPv4), so the length is 4 - The destination IP address (IPv4), so the length is 4 - The next-hop IP address (IPv4), so the length is 4 - The number of bytes of the Flow - The number of packets of the Flow Therefore, the Template FlowSet 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 0 | Length = 28 bytes | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 256 | Field Count = 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP_SRC_ADDR = 0x0008 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP_DST_ADDR = 0x000C | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP_NEXT_HOP = 0x000F | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IN_PKTS = 0x0002 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IN_BYTES = 0x0001 | Field Length = 4 | Claise, et. al Standard Track [Page 44] IPFIX Protocol Specifications January 2004 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 17.3 Data FlowSet Example In this example, we report the following three Flow records: Src IP addr. | Dst IP addr. | Next Hop addr. | Packet | Bytes | | | Number | Number --------------------------------------------------------------- 198.168.1.12 | 10.5.12.254 | 192.168.1.1 | 5009 | 5344385 192.168.1.27 | 10.5.12.23 | 192.168.1.1 | 748 | 388934 192.168.1.56 | 10.5.12.65 | 192.168.1.1 | 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 256 | Length = 64 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 198.168.1.12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 10.5.12.254 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.168.1.1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 5009 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 5344385 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.168.1.27 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 10.5.12.23 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.168.1.1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 748 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 388934 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.168.1.56 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 10.5.12.65 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.168.1.1 | Claise, et. al Standard Track [Page 45] IPFIX Protocol Specifications January 2004 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 6534 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note that padding was not necessary in this example. 17.4 Options Template FlowSet Example Per line card (the router being composed of two line cards), we want to report the following Field Types: - Total number of IPFIX Messages - Total number of exported Flows The format of the Options Template FlowSet 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 1 | Length = 24 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 257 | Option Scope Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Length = 8 | Scope 1 Field Type = 0x0003 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope 1 Field Length = 2 | TOTAL_EXP_PKTS_SENT = 41 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 | TOTAL_FLOWS_EXP = 42 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 17.5 Data FlowSet with Options Data Records Example In this example, we report the following two records: Line Card ID | IPFIX Message| Export Flow ------------------------------------------ Line Card 1 | 345 | 10201 Line Card 2 | 690 | 20402 0 1 2 3 Claise, et. al Standard Track [Page 46] IPFIX Protocol Specifications January 2004 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 257 | Length = 14 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | 345 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 10201 | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | 690 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 20402 | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 18. References 18.1 Normative References [IPFIX-ARCH] Sadasivan, G, Brownlee, N. "Architecture Model for IP Flow Information Export" draft-ietf-ipfix-arch-01.txt", June 2003 [IPFIX-INFO] Calato, P, Meyer, J, Quittek, J, "Information Model for IP Flow Information Export" draft-ietf-ipfix-info-02, August 2003 [IPFIX-AS] Claise, B, Fullmer, M, Calato, P, Penno, R, "IPFIX Protocol Specifications", draft-ietf-ipfix-protocol-00.txt, June 2003 [TCP] "TRANSMISSION CONTROL PROTOCOL DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION" RFC 793, September 1981 [RFC2960] Stewart, R. (ed.) "Stream Control Transmission Protocol", RFC 2960, October 2000 [PR-SCTP] Stewart, R, Ramalho, M, Xie, Q, Tuexen, M, Conrad, P. "SCTP Partial Reliability Extension", draft-ietf-tswg-prsctp-02.txt [NETFLOW9] Claise, B, et al "Cisco Systems NetFlow Services Export Version 9", draft-claise-netflow-9-06.txt, October 2003 18.2 Informative References Claise, et. al Standard Track [Page 47] IPFIX Protocol Specifications January 2004 [IPFIX-REQ] Quittek, J, Zseby, T, Claise, B, Zander, S, "Requirements for IP Flow Information Export" draft-ietf-ipfix-reqs- 10.txt, June 2003 [IPFIX-AS] Zseby, T, Penno, R, Brownlee, N, Claise, B, "IPFIX Applicability", draft-ietf-ipfix-as-01.txt, October 2003 [IPFIX-EVAL] Leinen, S, "Evaluation of Candidate Protocols for IP Flow Information Export (IPFIX)", draft-leinen-ipfix-eval-contrib- 01.txt, June 2003 [NETFLOW9] Claise, B, et al "Cisco Systems NetFlow Services Export Version 9", draft-claise-netflow-9-06.txt, October 2003 [PEN] IANA Private Enterprise Numbers registry http://www.iana.org/assignments/enterprise-numbers [USEIPSEC] S. Bellovin, Guidelines for Mandating the Use of IPsec, draft-bellovin-useipsec-02.txt, October 2003, work in progress. [L2TPv3] J. Lau et al. Layer Two Tunneling Protocol (Version 3) draft-ietf-l2tpext-l2tp-base-11.txt, October 2003, work in progress. [XXX-REFERENCE] [XXX-SCTP-BLIND-SPOOFING-REFERENCE] 19. Acknowledgments To be completed. Authors Addresses Benoit Claise Cisco Systems De Kleetlaan 6a b1 1831 Diegem Belgium Phone: +32 2 704 5622 E-mail: bclaise@cisco.com Claise, et. al Standard Track [Page 48] IPFIX Protocol Specifications January 2004 Mark Fullmer OARnet 2455 North Star Rd. Columbus, Ohio 43221 Phone: +1 (614) 728-8100 Email: maf@eng.oar.net Reinaldo Penno Nortel Networks 2305 Mission College Blvd Santa Clara, CA 95054 Phone: +1 408.565.3023 Email: rpenno@nortelnetworks.com Paul Calato Riverstone Networks, Inc. 5200 Great America Parkway Santa Clara, CA 95054 USA Phone: +1 (603) 557-6913 Email: calato@riverstonenet.com Ganesh Sadasivan Cisco Systems, Inc. 170 W. Tasman Dr. San Jose, CA 95134 USA Phone: +1 (408) 527-0251 Email: gsadasiv@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 Claise, et. al Standard Track [Page 49]