Internet Draft Expiration: December 2003 B. Claise Document: draft-claise-netflow-9-02.txt Cisco Systems Category: Informational June 2003 Cisco Systems NetFlow Services Export Version 9 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 Cisco Systems NetFlow services that provide network administrators with access to IP flows information. The NetFlow services create flow records that are exported to a NetFlow collector. The exported flow records can be used for a variety of purposes, including network management and planning, accounting, departmental chargebacks, Internet Service Provider (ISP) billing, data warehousing, and data mining for marketing purposes. This document focuses on the most recent evolution of the NetFlow flow record export format, which is known as version 9. The distinguishing feature of the NetFlow version 9 export format, compared with previous formats, is that it is template based. The templates (collections of fields with the corresponding description of their structures and their semantics) provide a flexible and Claise Informational [Page 1]
Cisco Systems NetFlow Services Export Version 9 June 2003 extensible design to the flow record export format. This facilitates future enhancements to NetFlow services without requiring changes to the basic flow record export format. Another advantage is that only the required fields are exported within the flow record, which minimizes the consumed export bandwidth. Conventions used in this document 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. Introduction...................................................2 1.1 Overview...................................................2 1.2 Applications...............................................3 2. Terminology....................................................5 2.1 Terminology Summary Table..................................8 3. NetFlow High-Level Picture on the Exporter.....................8 3.1 The NetFlow Process on the Exporter........................8 3.2 Flow Expiration............................................9 3.3 Transport Protocol.........................................9 4. Packet Layout..................................................9 5. Export Packet Format..........................................11 5.1 Header Format.............................................11 5.2 Template FlowSet Format...................................13 5.3 Data FlowSet Format.......................................14 6. Options.......................................................15 6.1 Options Template FlowSet Format...........................16 6.2 Options Data Record Format................................18 7. Template Management...........................................19 8. Field Type Definitions........................................20 9. The Collector's Side..........................................26 10. Examples.....................................................26 10.1 Packet Header Example....................................27 10.2 Template FlowSet Example.................................27 10.3 Data FlowSet Example.....................................28 10.4 Options Template FlowSet Example.........................29 10.5 Data FlowSet with Options Data Records Example...........30 11. References...................................................30 12. Authors......................................................30 13. Acknowledgments..............................................31 1. Introduction 1.1 Overview Claise Informational [Page 2]
Cisco Systems NetFlow Services Export Version 9 June 2003 NetFlow services data can be used for a variety of purposes. A partial list is available in the next section. This paper discusses the most recent evolution of the NetFlow flow record format known as version 9. The distinguishing feature of the NetFlow version 9 format, compared with previous formats, is that it is template based. A template is a collection of fields with corresponding descriptions of their structures and their semantics. This approach provides the following advantages: - Using the template mechanism, new fields can be added to NetFlow flow records without changing the structure of the export record format. With previous NetFlow versions, adding a new field in the flow record implied a new version of the export protocol format and a new version of the NetFlow collector that supports the parsing of this new export protocol format. - Templates that are sent to the collector contain the structural information about the exported flow records fields. Therefore, if the collector does not understand the semantics of new fields, it can still interpret the flow record. - Because the template mechanism is flexible, it allows the export of only the required fields from the flows to the NetFlow collector. This helps to reduce the exported flow data volume and possibly provide memory savings at the exporter and collector. Sending only the required information can also reduce network load. 1.2 Applications NetFlow services data enables several critical customer applications: Accounting and Billing NetFlow services data provides fine-grained metering (for example, flow records include details such as IP addresses, packet and byte counts, timestamps, Type of Service (ToS), application ports, etc.) for highly flexible and detailed resource usage accounting. ISPs can use this information to migrate from single fee, flat-rate billing to more flexible charging mechanisms based on time of day, bandwidth usage, application usage, quality of service, etc. Enterprise customers can use this information for departmental chargeback or cost allocation for resource usage. Claise Informational [Page 3]
Cisco Systems NetFlow Services Export Version 9 June 2003 Network Planning NetFlow services data captured over a long period of time can be used to track and anticipate network growth and plan upgrades to increase the number of routing devices, ports, or higher-bandwidth interfaces. NetFlow services data optimizes both strategic network planning (peering, backbone upgrade planning, and routing policy planning) as well as tactical network engineering decisions (upgrading the router or link capacity). This helps to minimize the total cost of network operations while maximizing network performance, capacity, and reliability. Peering Agreements NetFlow services data enables ISP peering partners to measure the volume and characteristics of traffic exchanged with other ISP peers. Traffic Engineering NetFlow services data provides traffic engineering details for a set of prefixes. This data can be used in network optimization for load balancing traffic across alternate paths, or for forwarding traffic of a certain set of prefixes on a preferred route. Network Monitoring NetFlow services data enables extensive near real-time network monitoring capabilities. NetFlow services data analysis can be used to display traffic patterns associated with routing devices and switches on an individual or network wide basis. This can display traffic or application-based views and therefore provide proactive problem detection, efficient troubleshooting, and rapid problem resolution. Application Monitoring and Profiling NetFlow services data enables content and service providers to view detailed, time-based, and application-based usage of a network. This information allows planning and allocation of network and application resources (such as Web server, gaming, or multimedia). User Monitoring and Profiling NetFlow services data provides a detailed understanding of customer or end-user usage of network and application resources. This information can then be used to efficiently plan and allocate Claise Informational [Page 4]
Cisco Systems NetFlow Services Export Version 9 June 2003 access, backbone, and application resources, as well as to detect and resolve potential security and policy violations. Security Analysis NetFlow services data provides details on source and destination addresses, along with the start time of flows and application ports. This data can be used to analyze network security and identify attacks. NetFlow Data Warehousing and Mining NetFlow services data (or derived information) can be stored for later retrieval and analysis to support proactive marketing and customer service programs. An example of this would be to determine which applications and services are being used by internal and external users and then target them for improved service such as advertising. This is especially useful for ISPs because NetFlow services data enables them to create better service packaging. 2. Terminology Various terms used in this document are described below: IP Flow or Flow A Flow is defined as a set of IP packets passing an Observation Point in the network during a certain time interval. All packets that belong to a particular Flow have a set of common properties derived from the data contained in the packet and from the packet treatment at the Observation Point. Flow Record A Flow Record provides information about an IP Flow that exists on the Exporter. In this document, the Flow Records are also referred to as NetFlow services data, NetFlow data, or Flow Data Record. Exporter A device (for example, a router) with NetFlow services enabled, the Exporter monitors packets entering an Observation Point and creates Flows out of these packets. The information from these Flows is exported in the form of Flow Records to the NetFlow Collector. NetFlow Collector The NetFlow Collector receives Flow Records from one or more Exporters. It processes the received Export Packet(s); that is Claise Informational [Page 5]
Cisco Systems NetFlow Services Export Version 9 June 2003 parses and stores the Flow Record information. Flow records can be optionally aggregated before being stored on the hard disk. The NetFlow Collector is also referred to as the Collector in this document. Observation Point A location in the network where IP packets can be observed; for example, one or a set of interfaces of the Exporter. An Observation Domain is associated with every Observation Point. Observation Domain: The set of Observation Points, which is the largest aggregatable set of Flow information at the Exporter is termed an Observation Domain. Each Observation Domain presents itself as a unique ID to the NetFlow Collector for identifying the Export Packets it generates. For example, a router line card composed of several interfaces with each interface being an Observation Point. Export Packet An Export Packet is a packet originating at the Exporter that carries the Flow Records of this Exporter and whose destination is the NetFlow Collector. Packet Header The Packet Header is the first part of an Export Packet, which provides basic information about the packet such as the NetFlow version, number of records contained within the packet, sequence numbering, etc. FlowSet FlowSet is a generic term for a collection of records that have a similar structure. In an Export Packet, one or more FlowSets follow the Packet Header. There are three different types of FlowSets: Template FlowSet, Options Template FlowSet, and Data FlowSet. Options Template FlowSet and Data FlowSet are identified by the FlowSet IDs. An Export Packet contains one or more FlowSets, and the three FlowSet types can be mixed within the same Export Packet. FlowSet ID An ID used to distinguish the different FlowSets. FlowSet IDs between 0 and 255 are reserved. The Template FlowSet uses the fixed FlowSet ID of 0, and the Options Template FlowSet Claise Informational [Page 6]
Cisco Systems NetFlow Services Export Version 9 June 2003 uses the fixed FlowSet ID of 1. Data FlowSets have a FlowSet ID greater than 255. Template Record A Template Record defines the structure and interpretation of fields in a data record. Data records that correspond to a template MAY appear in the same and/or subsequent Export Packets. The template information is not necessarily carried in every Export Packet. As such, the NetFlow Collector MUST store the Template Record to interpret the corresponding data records that are received in subsequent data packets. Template FlowSet A Template FlowSet is a collection of one or more Template Records that have been grouped together in an Export Packet. A well-known FlowSet ID identifies the Template FlowSet. Template ID A unique number that distinguishes a Template Record from all other Template Records produced by the same Observation Domain. A NetFlow Collector that receives Export Packets from several Observation Domains from the same Exporter MUST be aware that the uniqueness of the Template ID is not guaranteed across Observation Domains. Options Template Record A Template Record that describes the format of the Flow measurement parameters (for example, the sampling algorithm used, sampling interval) used at the Exporter. Options Template FlowSet An Options Template FlowSet is a collection of one or more Options Template Records that have been grouped together in an Export Packet. A well-known FlowSet ID identifies the Options Template FlowSet. Options Data Record The data record that contains values of the Flow measurement parameters corresponding to an Options Template Record. Flow Data Record Claise Informational [Page 7]
Cisco Systems NetFlow Services Export Version 9 June 2003 The data record that contains values of the Flow parameters corresponding to a Template Record. In this document, Flow Data Record is also referred to as Flow Record. Data FlowSet A Data FlowSet is a collection of one or more Flow or Options Data Records that are grouped together in an Export Packet. A Data FlowSet contains records that belong to the same Template ID. Each Data FlowSet references a previously transmitted Template ID, which can be used to parse the data contained within the Flow Records. 2.1 Terminology Summary Table FlowSet Template Record Data Record +----------------------------------------------------------------+ | | | Flow Data Record(s) | | Data FlowSet | / | or | | | | Options Data Record(s) | +----------------------------------------------------------------+ | Template FlowSet | Template Record(s) | / | +----------------------------------------------------------------+ | 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. The Flow Data Record is linked to a Template Record, and the Options Data Record is linked to an Options Template 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. 3. NetFlow High-Level Picture on the Exporter 3.1 The NetFlow Process on the Exporter The description of the NetFlow process (for example, sampled NetFlow, full NetFlow, aggregation), which is the way in which Flows Claise Informational [Page 8]
Cisco Systems NetFlow Services Export Version 9 June 2003 are created from the observed IP packets, is beyond the scope of this document. 3.2 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 interval otherwise it is considered as an active flow. A Flow can be exported under the following conditions: 1. If the Exporter can detect the end of a Flow, it SHOULD export the Flow Records at the end of the Flow. For example, a Flow generated by TCP [3] type of traffic where the FIN or RST bits indicate the end of the Flow. 2. If the Flow has been inactive for a certain period of time. This inactivity timeout SHOULD be configurable, with a minimum value of 0 for an immediate expiration. For example, a Flow generated by UDP [2] type of traffic. 3. For long-lasting Flows, the Exporter SHOULD export the Flow Records on a regular basis. This periodicity SHOULD be configurable. 4. If the Exporter experiences internal constraints, a Flow MAY be forced to expire prematurely (for example, counters wrapping or low memory). 3.3 Transport Protocol To achieve efficiency in terms of processing at the Exporter while handling high volumes of Export Packets, the NetFlow Export Packets are encapsulated into UDP [2] datagrams for export to the NetFlow Collector. However, NetFlow version 9 has been designed to be transport protocol independent. Hence, it can also operate over congestion-aware protocols such as TCP [3] or SCTP [4]. Note that the Exporter can export to multiple Collectors, using independent transport protocols. 4. Packet Layout Claise Informational [Page 9]
Cisco Systems NetFlow Services Export Version 9 June 2003 An Export Packet consists of a Packet Header followed by one or more FlowSets. The FlowSets can be any of the possible three types: Template, Data, or Options Template. Export Packet: +--------+-------------------------------------------+ | | +----------+ +---------+ +----------+ | | Packet | | Template | | Data | | Options | | | Header | | FlowSet | | FlowSet | | Template | ... | | | | | | | | FlowSet | | | | +----------+ +---------+ +----------+ | +--------+-------------------------------------------+ The possible combinations that can occur in an Export Packet are: - An Export Packet that consists of interleaved Template, Data, and Options Template FlowSets. Export Packet: +--------+--------------------------------------------------------+ | | +----------+ +---------+ +-----------+ +---------+ | | Packet | | Template | | Data | | Options | | Data | | | Header | | FlowSet | | FlowSet | ... | Template | | FlowSet | | | | | | | | | FlowSet | | | | | | +----------+ +---------+ +-----------+ +---------+ | +--------+--------------------------------------------------------+ - An Export Packet consisting entirely of Data FlowSets. After the appropriate Template Records have been defined and transmitted to the NetFlow Collector device, the majority of Export Packets will consist solely of Data FlowSets. Export Packet: +--------+----------------------------------------------+ | | +---------+ +---------+ +---------+ | | Packet | | Data | ... | Data | ... | Data | | | Header | | FlowSet | ... | FlowSet | ... | FlowSet | | | | +---------+ +---------+ +---------+ | +--------+----------------------------------------------+ - An Export Packet consisting entirely of Template and Options Template FlowSets. The Exporter MAY transmit a packet containing Template FlowSets ahead of time to help ensure that the NetFlow Claise Informational [Page 10]
Cisco Systems NetFlow Services Export Version 9 June 2003 Collector has the correct Template Records before receiving the first Data FlowSet. Export Packet: +--------+-------------------------------------------------+ | | +----------+ +----------+ +----------+ | | Packet | | Template | | Template | | Options | | | Header | | FlowSet | ... | FlowSet | ... | Template | | | | | | | | | FlowSet | | | | +----------+ +----------+ +----------+ | +--------+-------------------------------------------------+ A Template FlowSet provides a description of the fields that would be present in future Data FlowSets. These Data FlowSets MAY occur later within the same Export Packet or in subsequent Export Packets. - An Export Packet consisting entirely of Options Template FlowSets and Data FlowSets containing Options Data Records, if there is only options data to be sent. Export Packet: +--------+-------------------------------------------------+ | | +----------+ +----------+ +----------+ | | Packet | | Options | | Data | | Data | | | Header | | Template | ... | FlowSet | ... | FlowSet | | | | | FlowSet | | | | | | | | +----------+ +----------+ +----------+ | +--------+-------------------------------------------------+ The format of the Template, Data, and Options Template FlowSets will be discussed later in this document. 5. Export Packet Format 5.1 Header Format Note that the Packet Header format is similar to the one developed by the different versions of NetFlow defined by Cisco, for backward compatibility. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Claise Informational [Page 11]
Cisco Systems NetFlow Services Export Version 9 June 2003 | Version Number | Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sysUpTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | UNIX Secs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Packet Header Field Descriptions Version Version of Flow Record format exported in this packet. The value of this field is 0x0009 for the current version. Count Count is the total number of record in the Export Packet, which is the sum total of Options FlowSet records, Template FlowSet records and Data FlowSet records. SysUpTime Time in milliseconds since this device was first booted. Refer to [1]. UNIX Secs Seconds since 0000 UTC 1970. Sequence Number Incremental sequence counter of all Export Packets sent from the current Observation Domain by the Exporter. This value will be cumulative, and can be used to identify whether any Export Packets have been missed. Source ID The Source ID field is a 32-bit value that identifies the Exporter Observation Domain. NetFlow Collectors SHOULD use the combination of the source IP address and the Source ID field to separate different export streams originating from the same Exporter. Claise Informational [Page 12]
Cisco Systems NetFlow Services Export Version 9 June 2003 5.2 Template FlowSet Format One of the essential elements in the NetFlow format is the Template FlowSet. Templates greatly enhance the flexibility of the Flow Record format because they allow the NetFlow Collector to process Flow Records without necessarily knowing the interpretation of all the data in the Flow Record. The format of the 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 = 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 FlowSet Field Descriptions FlowSet ID FlowSet ID value of 0 is reserved for Template FlowSet. Length Claise Informational [Page 13]
Cisco Systems NetFlow Services Export Version 9 June 2003 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 total of lengths of 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 FlowSet that would be created in the future. 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 Collector 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 the "Field Type Definitions" section. Field Length The length of the corresponding Field Type, in bytes. Refer to the "Field Type Definitions" section. 5.3 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 | ... | Claise Informational [Page 14]
Cisco Systems NetFlow Services Export Version 9 June 2003 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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 Collector 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 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 Padding SHOULD be inserted so that 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 Collector. 6. Options Claise Informational [Page 15]
Cisco Systems NetFlow Services Export Version 9 June 2003 6.1 Options Template FlowSet Format The Options Template Record (and its corresponding Options Data Record) is used to supply information about the NetFlow process configuration or NetFlow process specific data, rather than supplying information about IP Flows. For example, the sample rate of a specific interface, if sampling is supported, along with the sampling method used. The format of the Options Template FlowSet is detailed below: 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Options Template FlowSet Field Definitions 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. Claise Informational [Page 16]
Cisco Systems NetFlow Services Export Version 9 June 2003 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. Scope 1 Field Type The relevant portion of the Exporter/NetFlow process to which the Options Template Record refers. Currently defined values are: 0x0001 System 0x0002 Interface 0x0003 Line Card 0x0004 Cache 0x0005 Template For example, the NetFlow process can be implemented on a per-interface basis, so if the Options Template Record were reporting on how the NetFlow process is configured, the Scope for the report would be 0x0002 (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 which all have to 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 Claise Informational [Page 17]
Cisco Systems NetFlow Services Export Version 9 June 2003 A numeric value that represents the type of field that would appear in the Options Template Record. Refer to the Field Type Definitions section. Option 1 Field Length The length (in bytes) of the Option Field. Padding Padding SHOULD be inserted 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. 6.2 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 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 - 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Claise Informational [Page 18]
Cisco Systems NetFlow Services Export Version 9 June 2003 Options Data Records of the Data FlowSet Field Descriptions FlowSet ID = Template ID Each group of Options Data Records within a Data FlowSet is preceded by a FlowSet ID. The FlowSet ID maps to a (previously generated) Template ID corresponding to this Options Template Record. The Collector MUST use the FlowSet ID to map the appropriate type and length to any field values that follow. Length The length of this FlowSet. Length is the sum total of lengths of 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 field types and values. The Type and Length of the fields have been previously defined in the Options Template Record referenced by the FlowSet ID or Template ID. Padding Padding SHOULD be inserted 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 Collector. 7. Template Management The Template IDs must remain constant for the life of the NetFlow process and the Exporter. If the Exporter or the NetFlow 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 Exporter or NetFlow process restart. A newly created Template Record is assigned an unused Template ID from the Exporter. If the template configuration is changed, the Claise Informational [Page 19]
Cisco Systems NetFlow Services Export Version 9 June 2003 current Template ID is abandoned and not reused until the NetFlow process or Exporter restarts. If a configured Template Record on the Exporter is deleted, and re- configured with exactly the same parameters, the same Template ID COULD be reused. The Exporter sends the Template FlowSet and Options Template FlowSet under the following conditions: 1. After a NetFlow process restarts, the Exporter MUST NOT send any Data FlowSet without having the corresponding Template FlowSet and the required Options Template FlowSet sent out in a previous packet or in the same Export Packet. It MAY transmit the Template FlowSet and Options Template FlowSet, without any Data FlowSets, ahead of time 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 Exporter SHOULD send the incremental changes at an accelerated rate. In such a case, it MAY transmit the changed Template Record(s) and Options Template Record(s), without any data, ahead of time to help ensure that the Collector will have the correct template information before receiving the first data. 3. On a regular basis, the Exporter MUST send all the Template Records and Options Template Records to refresh the Collector. Template IDs have a limited lifetime at the Collector and MUST be periodically refreshed. Two approaches are taken to make sure that Templates get refreshed at the Collector: * Every N number of Export Packets. * On a time basis, so every N number of minutes. Both options MUST be configurable by the user. When one of these expiry conditions is met, the Exporter MUST send the Template FlowSet and Options Template. 8. Field Type Definitions The following table describes all the field type definitions that an Exporter MAY support. The fields are a selection of Packet Header fields, lookup results (for example the autonomous system numbers or Claise Informational [Page 20]
Cisco Systems NetFlow Services Export Version 9 June 2003 the subnet masks), and properties of the packet itself such as length. Field Type Value Length Description (bytes) Incoming counter with length IN_BYTES 1 N N x 8 bits for bytes associated with an IP Flow Incoming counter with length IN_PKTS 2 N N x 8 bits for packets associated with an IP Flow FLOWS 3 N Number of Flows that were aggregated; by default N is 4 PROTOCOL 4 1 IP protocol byte TOS 5 1 Type of service byte TCP_FLAGS 6 1 TCP flags; cumulative of all the TCP flags seen in this Flow TCP/UDP source port number L4_SRC_PORT 7 2 (for example, FTP, Telnet, or equivalent) IPV4_SRC_ADDR 8 4 IPv4 source address SRC_MASK 9 1 Source route mask bits Input interface index. INPUT_SNMP 10 N By default N is 2, but higher values can be used TCP/UDP destination port L4_DST_PORT 11 2 number (for example, FTP, Telnet, or equivalent) Claise Informational [Page 21]
Cisco Systems NetFlow Services Export Version 9 June 2003 IPV4_DST_ADDR 12 4 IPv4 destination address DST_MASK 13 1 Destination route mask bits Output interface index. OUTPUT_SNMP 14 N By default N is 2, but higher values can be used IPV4_NEXT_HOP 15 4 IPv4 address of the next-hop router Source BGP autonomous SRC_AS 16 N system number where N could be 2 or 4 Destination BGP autonomous DST_AS 17 N system number where N could be 2 or 4 BGP_IPV4_NEXT_HOP 18 4 Next-hop router's IP in the BGP domain IP multicast outgoing MUL_DST_PKTS 19 N packet counter with length N x 8 bits for packets associated with the IP Flow IP multicast outgoing MUL_DST_BYTES 20 N Octet (byte) counter with length N x 8 bits for bytes associated with the IP Flow SysUptime at which the LAST_SWITCHED 21 4 last packet of this Flow was switched SysUptime at which the FIRST_SWITCHED 22 4 first packet of this Flow was switched IPV6_SRC_ADDR 27 16 IPv6 source address Claise Informational [Page 22]
Cisco Systems NetFlow Services Export Version 9 June 2003 IPV6_DST_ADDR 28 16 IPv6 destination address IPV6_SRC_MASK 29 1 Length of the IPv6 source mask in contiguous bits IPV6_DST_MASK 30 1 Length of the IPv6 destination mask in contiguous bits Flow identifier for a given FLOW_LABEL 31 3 source/destination pair of IPv6 traffic Internet Control Message ICMP_TYPE 32 2 Protocol (ICMP) packet type; reported as ICMP Type * 256 + ICMP code IGMP_TYPE 33 1 Internet Group Management Protocol (IGMP) packet type When using sampled NetFlow, the rate at which packets SAMPLING_INTERVAL 34 4 are sampled; for example, a value of 100 indicates that one of every hundred packets is sampled The type of algorithm used for sampled NetFlow: SAMPLING_ALGO 35 1 0x01 interval packet sampling 0x02 pseudorandom sampling Timeout value (in seconds) FLOW_ACTIVE_TIMEOUT 36 2 for active Flow entries in the NetFlow cache Timeout value (in seconds) FLOW_INACTIVE_TIMEOUT 37 2 for inactive Flow entries in the NetFlow cache Claise Informational [Page 23]
Cisco Systems NetFlow Services Export Version 9 June 2003 ENGINE_TYPE 38 1 Type of Flow switching engine ENGINE_ID 39 1 ID number of the Flow switching engine Counter with length N x 8 bits for bytes TOTAL_BYTES_EXPORTED 40 N for the number of bytes exported by the Observation Domain Counter with length N x 8 bits for bytes TOTAL_EXP_PKTS_SENT 41 N for the number of packets exported by the Observation Domain Counter with length N x 8 bits for bytes TOTAL_FLOWS_EXP 42 N for the number of Flows exported by the Observation Domain Internet Protocol Version Set to 4 for IPv4, set to 6 IP_PROTOCOL_VERSION 60 1 for IPv6. If not present in the template, then version 4 is assumed Flow direction: DIRECTION 61 1 0 - ingress flow 1 รป egress flow IPV6_NEXT_HOP 62 16 IPv6 address of the next-hop router BPG_IPV6_NEXT_HOP 63 16 Next-hop router in the BGP domain Bit-encoded field IPV6_OPTION_HEADERS 64 4 identifying IPv6 option Claise Informational [Page 24]
Cisco Systems NetFlow Services Export Version 9 June 2003 headers found in the flow MPLS_LABEL_1 70 3 MPLS label at position 1 in the stack MPLS_LABEL_2 71 3 MPLS label at position 2 in the stack MPLS_LABEL_3 72 3 MPLS label at position 3 in the stack MPLS_LABEL_4 73 3 MPLS label at position 4 in the stack MPLS_LABEL_5 74 3 MPLS label at position 5 in the stack MPLS_LABEL_6 75 3 MPLS label at position 6 in the stack MPLS_LABEL_7 76 3 MPLS label at position 7 in the stack MPLS_LABEL_8 77 3 MPLS label at position 8 in the stack MPLS_LABEL_9 78 3 MPLS label at position 9 in the stack MPLS_LABEL_10 79 3 MPLS label at position 10 in the stack The value field is a numeric identifier for the field type. The following value fields are reserved: from 23 to 26, from 43 to 59, and from 65 to 69. When extensibility is required, the new field types will be added to the list. The new field types have to be updated on the Exporter and Collector but the NetFlow export format would remain unchanged. Refer to the latest documentation at http://www.cisco.com for the newly updated list. Claise Informational [Page 25]
Cisco Systems NetFlow Services Export Version 9 June 2003 9. The Collector's Side The Collector will receive Template Records from the Exporter, 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 Collector SHOULD store the Flow Data Records (or Options Data Records) and decode them after the Template Records are received. A Collector device MUST NOT assume that the Data FlowSet and the associated Template FlowSet (or Options Template FlowSet) are exported in the same Export Packet. The Collector MUST NOT assume that one and only one Template FlowSet is present in an Export Packet. The life of a template at the Collector is limited to a fixed refresh timeout. Templates not refreshed from the Exporter within the timeout are expired at the Collector. The Collector MUST NOT attempt to decode the Flow or Options Data Records with an expired Template. At any given time the Collector SHOULD maintain the following for all the current Template Records and Options Template Records: <Exporter, Observation Domain, Template ID, Template Definition, Last Received> Note that the Observation Domain is identified by the Source ID field from the Export Packet. Template IDs are unique per Exporter and per Observation Domain. If a new Template Record is received on the Collector (for example in the case of an Exporter restart) it MUST immediately override the existing Template Record. 10. Examples Let's consider the example of an Export Packet 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). Export Packet: +--------+---------------------------------------------. . . | | +--------------+ +-----------------------+ Claise Informational [Page 26]
Cisco Systems NetFlow Services Export Version 9 June 2003 | Packet | | Template | | Data | | Header | | FlowSet | | FlowSet | . . . | | | (1 Template) | | (3 Flow Data Records) | | | +--------------+ +-----------------------+ +--------+---------------------------------------------. . . . . .+-------------------------------------------------+ +------------------+ +--------------------------+ | | Options | | Data | | . . .| Template FlowSet | | FlowSet | | | (1 Template) | | (2 Options Data Records) | | +------------------+ +--------------------------+ | . . .--------------------------------------------------+ 10.1 Packet Header Example The Packet 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 | Count = 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sysUpTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | UNIX Secs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10.2 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: Claise Informational [Page 27]
Cisco Systems NetFlow Services Export Version 9 June 2003 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10.3 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 | Claise Informational [Page 28]
Cisco Systems NetFlow Services Export Version 9 June 2003 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note that padding was not necessary in this example. 10.4 Options Template FlowSet Example Per line card (the Exporter being composed of two line cards), we want to report the following Field Types: - Total number of Export Packets - 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 | Claise Informational [Page 29]
Cisco Systems NetFlow Services Export Version 9 June 2003 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 | TOTAL_FLOWS_EXP = 42 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10.5 Data FlowSet with Options Data Records Example In this example, we report the following two records: Line Card ID | Export Packet| Export Flow ------------------------------------------ Line Card 1 | 345 | 10201 Line Card 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FlowSet ID = 257 | Length = 14 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | 345 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 10201 | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | 690 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 20402 | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 11. References [1] R. Presuhn et al, "Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)" RFC 3418, December 2002 [2] J. Postel, "User Datagram Protocol" RFC 768, August 1980 [3] "TRANSMISSION CONTROL PROTOCOL DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION" RFC 793, September 1981 [4] R. Stewart et al, "Stream Control Transmission Protocol" RFC 2960, October 2000 12. Authors Claise Informational [Page 30]
Cisco Systems NetFlow Services Export Version 9 June 2003 This document was jointly written by Vamsidhar Valluri, Martin Djernaes, Ganesh Sadasivan, and Benoit Claise. 13. Acknowledgments I would like to thank Pritam Shah and Paul Kohler for their valuable technical feedback. Authors Addresses Benoit Claise Cisco Systems De Kleetlaan 6a b1 1831 Diegem Belgium Phone: +32 2 704 5622 E-mail: bclaise@cisco.com Ganesh Sadasivan Cisco Systems, Inc. 3750 Cisco Way San Jose, CA 95134 USA Phone: +1 408 527-0251 E-mail: gsadasiv@cisco.com Vamsi Valluri Cisco Systems, Inc. 510 McCarthy Blvd. San Jose, CA 95035 USA Phone: +1 408 525-1835 E-mail: vvalluri@cisco.com Martin Djernaes Cisco Systems, Inc. 510 McCarthy Blvd. San Jose, CA 95035 USA Phone: +1 408 853-1676 E-mail: djernaes@cisco.com Claise Informational [Page 31]