Internet Draft B. Claise Document: draft-claise-ipfix-eval-netflow-00.txt Cisco Systems Expires: Mars 2003 September 2002 Evaluation Of NetFlow Version 9 Against IPFIX Requirements Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of [RFC 2026]. 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 Distribution of this document is unlimited. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract This document provides an evaluation of the applicability of the NetFlow flow record export protocol version 9 as an IPFIX protocol. It compares the properties and capabilities of the NetFlow flow record export protocol version 9 to the IPFIX requirements [IPFIX-REQ]. This document is the first version of the draft and should not be considered as finished work. Updated version(s) will soon follow with Claise Expires û February 2003 [Page 1] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 changes introduced by the publication of the new requirement draft version 6 [IPFIX-REQ6], and with the English syntax and grammar corrections. Table of Contents 1. Introduction...................................................3 2. Architectural Considerations...................................5 2.1 NetFlow Protocol Overview..................................6 2.2 General Applicability......................................6 2.2.1 Flow Definition......................................6 2.2.2 Observation Point....................................7 2.2.3 The Metering Process and the Flow Record.............7 2.2.4 The Exporting Process................................7 2.2.5 The Collecting Process...............................7 2.3 Architectural Differences..................................8 3. Item Level Compliance Evaluation...............................9 3.1 Terminology (section 2)....................................9 3.1.1 IP Traffic Flow (2.1)................................9 3.1.2 Observation Point (2.2)..............................9 3.1.3 Metering Process (2.3)..............................10 3.1.4 Flow Record (2.4)...................................10 3.1.5 Exporting Process (2.5).............................10 3.1.6 Collecting Process (2.6)............................10 3.2 Applications Requiring IP Flow Information Export (3).....10 3.3 Distinguishing Flows (4)..................................11 3.3.1 Interface (4.1).....................................11 3.3.2 IP Header Fields (4.2)..............................11 3.3.3 Transport Header Fields (4.3).......................11 3.3.4 MPLS (4.4)..........................................11 3.3.5 DiffServ Code Point (4.5)...........................11 3.3.6 Header Compression and Encryption (4.6).............11 3.4 Metering Process (5)......................................11 3.4.1 Reliability (5.1)...................................12 3.4.2 Sampling (5.2)......................................12 3.4.3 Overload Behavior (5.3).............................12 3.4.4 Timestamps (5.4)....................................13 3.4.5 Time Synchronization (5.5)..........................13 3.4.6 Flow Expiration (5.6)...............................13 3.4.7 Multicast (5.7).....................................14 3.4.8 Ignore Port Copy (5.8)..............................14 3.5 Data Export (6)...........................................14 3.5.1 Information Model (6.1).............................14 3.5.2 Data Model (6.2)....................................15 3.5.3 Data Transfer (6.3).................................15 3.5.3.1 Congestion Awareness (6.3.1)....................15 3.5.3.2 Reliability (6.3.2).............................15 Claise Expires û Mars 2003 [Page 2] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 3.5.3.3 Security (6.3.3)................................15 3.5.4 Regular Reporting Interval (6.4)....................16 3.5.5 Notification on Specific Events (6.5)...............16 3.5.6 Anonymization (6.6).................................16 3.6 Configuration (7).........................................16 3.6.1 Configuration of the Metering Process (7.1).........16 3.6.2 Configuration of the Exporting Process (7.2)........16 3.7 General Requirements Compliance (8).......................16 3.7.1 Openness (8.1)......................................16 3.7.2 Scalability Concerning the Number of Exporting Processes (8.2) 16 3.7.3 Several Collecting Processes (8.3)..................17 4. Security Considerations.......................................17 5. References....................................................17 6. Author's Address..............................................18 7. Full Copyright Statement......................................18 1. Introduction This document provides an evaluation of the applicability of the NetFlow flow record export protocol version 9 as an IPFIX protocol. First, the general NetFlow architecture is introduced and its application to the communication between an IPFIX exporting process and an IPFIX collecting process is discussed in Section 2. Section 3 discusses in detail, to which degree requirements stated in [IPFIX-REQ] are met. This document uses the terminology defined in [IPFIX-REQ]. Note that the generic term NetFlow refers to multiple different notions: the metering process, the exporting process and the export protocol, as defined in the IPFIX terminology section of [IPFIX-REQ]. Even if the metering process and exporting process form a single NetFlow process on the Cisco Systems devices, this document will sometimes refer to NetFlow metering process and NetFlow exporting process for the sake of clarity. But the export protocol will always be referred to as the NetFlow flow record export protocol version 9. - How and where is it documented? All documentation related to NetFlow can be found at: http://www.cisco.com/go/netflow More specifically, the ôNetFlow Services Solutions Guideö covers a NetFlow overview, the basic and advanced concepts, the explanation of the Claise Expires û Mars 2003 [Page 3] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 different versions along with the data types exported, some configuration examples, etc. For reference, see: http://www.cisco.com/univercd/cc/td/doc/cisintwk/intsolns/netflsol/nfwhite .htm The new flexible and extensible NetFlow flow record export version 9 is described in the IETF draft "Cisco Systems NetFlow Services Export Version 9" [NETFLOW9], as well as in the following document: http://www.cisco.com/warp/public/cc/pd/iosw/prodlit/ntfo_wp.htm - Are there concrete plans for standardizing it? The way to standardize NetFlow is via the IETF IPFIX Working Group. In parallel, Cisco Systems intention is to produce an Information RFC out of [NETFLOW9]. - Is standardization already in progress? No other standardization than the participation to the IETF IPFIX Working Group is currently taking place. - Is it proprietary to a certain company? NetFlow is a proprietary protocol from Cisco Systems. - Does it include any technology protected by patents? NetFlow is protected by the following patent: United States Patent 6,243,667 Kerr, et al. June 5, 2001 Abstract: The invention provides a method and system for switching in networks responsive to message flow patterns. A message "flow" is defined to comprise a set of packets to be transmitted between a particular source and a particular destination. When routers in a network identify a new message flow, they determine the proper processing for packets in that message flow and cache that information for that message flow. Thereafter, when routers in a network identify a packet which is part of that message flow, they process that packet according to the proper processing for packets in that message flow. The proper processing may include a determination of a destination port for routing those packets and a determination of whether access control permits routing those packets to their indicated destination. Claise Expires û Mars 2003 [Page 4] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 Nevertheless, Cisco Systems has no intention to use this patent to prevent other vendors to implement a NetFlow-like solution. An Intellectual Property Right message has been sent to the IETF rfc- editor team to post a similar message at http://www.ietf.org/ipr.html - Is it already implemented? The NetFlow flow record export protocol version 9 protocol is currently at the stage of the Early Field Test, while NetFlow flow record export versions 1, 5, 7 and 8 have been implemented for years now. - Is it already in commercial use? Some Cisco Systems partners are currently developing NetFlow Collectors (the correct term is ôcollecting processö according to [IPFIX-REQ]) able to receive NetFlow version 9 flow records. While many different companies or organizations have already implemented NetFlow Collectors for the previous NetFlow flow record export protocols versions. Ex: Concord Communications, Hewlett Packard, Narus, Xacct, Portal, Apogee Networks, Infovista, etc. to name just a few. - Is it available from more than one source? As the inventor of NetFlow, Cisco Systems is the only company implementing this new version 9 on its devices. But, if we speak of the previous NetFlow flow record export protocol versions, then the majority of our competitors implemented those versions. - Is it already widely used? The new NetFlow flow record export protocol version 9 is in Early Field Test right now, while the previous NetFlow flow record export versions have been implemented by our competitors. As a consequence, NetFlow is widely used through out the industry. 2. Architectural Considerations This section introduces the architecture of the NetFlow and suggests a way of applying it to the communication between an IPFIX exporting process and an IPFIX collecting process. Claise Expires û Mars 2003 [Page 5] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 2.1 NetFlow Protocol Overview This section discusses the most recent evolution of the NetFlow flow record export protocol, which is known as Version 9. The distinguishing feature of the NetFlow Version 9 format compared to the previous versions, is that it is template based. Template is a collection of fields along with the description of their structure and semantics. This approach gives the following advantages: - The template mechanism being flexible, allows the export of the required fields alone from the IP Flows to the collecting process. This helps to reduce the exported flow data volume, and possible memory savings at the metering process and collecting process. Sending the required information only, reduces the network load too. - Using the template mechanism, new fields can be added to NetFlow export records without changing the structure of export record format. With the previous NetFlow flow record export versions, adding a new field in the flow record implied a new version of the export protocol format and a new version of the collecting process that supports the parsing of this new export protocol format. - Templates which are sent to the collecting process contains the structural information about the exported Flow Records fields. So, even if the collecting process does not understand the semantics of new fields, it can still interpret the Flow Record. - Even if the NetFlow flow record export protocol version 9 has been created with a IP flow record background in mind, note that Information Model can be extended with any data types and could potentially serve any reporting purposes. E.g. the NetFlow metering process configuration. 2.2 General Applicability 2.2.1 Flow Definition A NetFlow flow is identified as a unidirectional stream of packets between a given source and destinationùboth defined by a network-layer IP address Claise Expires û Mars 2003 [Page 6] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 and transport-layer source and destination port numbers. Typically in case of ingress NetFlow, a flow is identified as the combination of the following seven key fields: source IP address, destination IP address, source port number, destination port number, layer 3 protocol type, ToS byte, input logical interface (ifIndex). In case of egress NetFlow, a flow is identified as the combination of the following seven key fields: source IP address, destination IP address, source port number, destination port number, layer 3 protocol type, ToS byte, output logical interface (ifIndex). These seven key fields define a unique flow. If a new observed packet contains a different set of these seven key fields, then this packet will create a new flow. Note that a flow contains other accounting fields (such as the number of packets, number of bytes, the BGP AS, etc). 2.2.2 Observation Point NetFlow is enabled in most case per interface (per port), sometimes per subinterface. On specific device, NetFlow is enabled for the entire platform. 2.2.3 The Metering Process and the Flow Record NetFlow operates by creating a NetFlow cache that contains the information for all active flows. A flow record is maintained within the NetFlow cache for all active flows. Each flow record in the NetFlow cache contains key fields that can be later used for exporting to a collecting process. 2.2.4 The Exporting Process The NetFlow enabled platform checks the NetFlow cache once per second and expires the flow if no more traffic of that flow is observed. Once expired, the flow records are directly exported to the collecting process. To achieve efficiency in terms of processing at the Exporter while handling high volume of export, the NetFlow export packet is encapsulated into UDP [UDP] datagrams for export to the collecting process. Nevertheless NetFlow flow record export protocol version 9 has been designed to be transport protocol independent. Hence, it can also operate over congestion aware protocols like TCP [TCP] or SCTP [SCTP]. 2.2.5 The Collecting Process Claise Expires û Mars 2003 [Page 7] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 NetFlow Collector (the collecting process) provides the data collection from multiple export devices exporting NetFlow flow records. It will process and store the flow records. Some extra actions on these flow records could be executed on the collecting process but per [IPFIX-REQ], these actions are out of the scope of the IPFIX work. 2.3 Architectural Differences +----------------+ +----------------+ |[*Application 1]| ..|[*Application n]| +--------+-------+ +-------+--------+ ^ ^ ~ ~ +~~~~~~~~~~+~~~~~~~~+ ! v +----------------------+ +------------------+ |Device(i) | | Collector(j) | |[Obsv Point(s)] |--------------->| [*Application(s)]| |[Metering Process(es)]| +---->| | |[Export Process] | | +------------------+ +----------------------+ . .... . +----------------------+ | |Device(m) | | |[Obsv Point(s)] |----------+ |[Metering Process(es)]| |[Export Process] | +----------------------+ Except the terminology difference again described below, there is no difference between the NetFlow and IPFIX architecture. Note that the generic term NetFlow refers to multiple different notions: the metering process, the exporting process and the export protocol, as defined in the IPFIX terminology section of [IPFIX-REQ]. Even if the metering process and exporting process form a single NetFlow process on the Cisco Systems devices, this document will sometimes refer to NetFlow metering process and NetFlow exporting process for the sake of clarity. But the export protocol will always be referred to as the NetFlow flow record export protocol version 9. Claise Expires û Mars 2003 [Page 8] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 3. Item Level Compliance Evaluation This section evaluates the compliance of the NetFlow protocol with the IPFIX requirements item by item. Requirements are addressed by their section numbers and item numbers in [IPFIX-REQ]. For each requirement it is explained to what degree protocol NetFlow flow export version 9 meets the requirement and how this is achieved. The degree of compliancy is explicitly stated using five grades: -T Total compliance: The requirement is met completely by the protocol specification without any extensions required. -E Extension required for total compliance: The protocol is prepared to be extended and it is possible to extend it in a way that it meets the requirement. This grade is only applicable to protocols that are explicitly open to externally defined extensions, such as SNMP is extended by MIB modules or DIAMETER is extended by application modules. It is not applicable to protocols, where the protocol specification itself needs to be extended in order to comply with the requirement. -P Partial compliance: The requirement is met partially by the protocol specification. -U Upcoming compliance: The requirement is not met or met partially by the protocol specification, but there is a concrete plan for an upcoming version of the protocol. -F Failed compliance: The requirement is not met by the protocol specification. 3.1 Terminology (section 2) 3.1.1 IP Traffic Flow (2.1) Total compliance of NetFlow Flow definition with the IPFIX IP Traffic Flow definition. 3.1.2 Observation Point (2.2) Claise Expires û Mars 2003 [Page 9] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 Total compliance of NetFlow Observation Point definition with the IPFIX Observation Point definition. NetFlow is enabled by interface or per subinterface. NetFlow can be enable on multiple interfaces at the same time, e.g. all interfaces belonging to one line card, or all the interfaces from the device. On specific device, NetFlow is enabled for the entire platform. 3.1.3 Metering Process (2.3) Total compliance of NetFlow with the IPFIX Metering Process definition, for all aspects: packet header capturing, timestamping, sampling, classifying, and maintaining flow records. 3.1.4 Flow Record (2.4) Total compliance of NetFlow Flow Record definition with the IPFIX Flow Record definition. 3.1.5 Exporting Process (2.5) Total compliance of NetFlow Exporting Process with the IPFIX Exporting Process definition. The NetFlow Exporting Process may send the flow records to 2 different collecting processes. 3.1.6 Collecting Process (2.6) Total compliance of NetFlow Collector with the IPFIX collecting process definition. 3.2 Applications Requiring IP Flow Information Export (3) Total compliance of NetFlow regarding the different applications described in [IPFIX-REQ] which require IP flow information export, i.e. Usage-based Accounting, Traffic Profiling, Traffic Engineering, Attack/Intrusion Detection and QoS Monitoring. Actually, the Information Model associated with NetFlow flow record export version 9 [NETFLOW9] contains all the data types needed to satisfy the requirements of the different applications described in this section. Claise Expires û Mars 2003 [Page 10] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 3.3 Distinguishing Flows (4) 3.3.1 Interface (4.1) Total Compliance of the interface as a flow distinguisher. In case of ingress NetFlow, a flow is identified, amongst other fields, by the input logical interface (ifIndex). In case of egress NetFlow, a flow is identified, amongst other fields by output logical interface (ifIndex). 3.3.2 IP Header Fields (4.2) source IP address (MUST): Total Compliance destination IP address (MUST): Total Compliance protocol type (TCP,UDP,ICMP,...) (MUST): Total Compliance IP version number (SHOULD): Upcoming Compliance 3.3.3 Transport Header Fields (4.3) Total Compliance of the port numbers of the transport header as a flow distinguisher. 3.3.4 MPLS (4.4) Total Compliance of the MPLS label a flow distinguisher, if the observation point is located at a device supporting Multiprotocol Label Switching. 3.3.5 DiffServ Code Point (4.5) Partial Compliance, as NetFlow distinguish flow by the TOS field. 3.3.6 Header Compression and Encryption (4.6) Total Compliance. 3.4 Metering Process (5) Claise Expires û Mars 2003 [Page 11] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 3.4.1 Reliability (5.1) To be written. 3.4.2 Sampling (5.2) ôThe metering process MAY support packet sampling.ö, as defined in [IPFIX-REQ]ô. Total Compliance. NetFlow supports packet sampling. ôIf sampling is supported the sampling configuration MUST be well defined. The sampling configuration includes the sampling method and all its parameters.ö, as defined in [IPFIX-REQ]. Total compliance. See the Options Template from [NETFLOW9]: a template that describes the format of the Flow measurement parameters (like the sampling algorithm, sampling interval) done at the metering process. ôIf the sampling configuration is changed during operation, the new sampling configuration with its parameters MUST be indicated to all collecting processes receiving the affected flow records. Changing the sampling configuration includes: start sampling, stop sampling, change sampling method, and change sampling parameter.ô, as defined in [IPFIX-REQ]ô. Partial Compliance. NetFlow supports the ôchange sampling methodö and ôchange sampling parameterö options. 3.4.3 Overload Behavior (5.3) ôIn case of an overload, for example lack of memory or processing power, the metering process MAY change its behavior in order to cope with the lack of resources.ö, as defined in [IPFIX-REQ]. Total Compliance. ôBut in case the overload behavior has an impact on the metering process or the exporting process, the overload behavior MUST be clearly defined and the collecting process MUST be able to distinguish the flow records exported before and after the metering process behavior change:ö, as defined in [IPFIX-REQ]. If the metering process configuration is changed, then Total Compliance. But failed compliance in the following situation: in case the NetFlow cache becomes full, the flow records will be expired with a smaller timeout! In this specific case, this requirement doesnÆt make sense. ôIn case of any change of the meter's behavior, all flow records metered by the previous behavior MUST be terminated and exported Claise Expires û Mars 2003 [Page 12] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 according to the configuration of the exporting process.ö, as defined in [IPFIX-REQ]. Total Compliance. ôThe metering process MUST not merge the flow records generated with the new behavior with the flow records generated with the previous behavior.ö, as defined in [IPFIX-REQ]. If the metering process configuration is changed, then Total Compliance because a new Template ID for the new configuration will be generated. But failed compliance in the following situation: in case the NetFlow cache becomes full, the flow records will be expired with a smaller timeout! In this specific case, this requirement doesnÆt make sense. 3.4.4 Timestamps (5.4) Total Compliance. 3.4.5 Time Synchronization (5.5) The compliance is not relevant as the mechanism used for time synchronization is outside the scope of the IPFIX. 3.4.6 Flow Expiration (5.6) Total Compliance of the NetFlow flow expiration mechanism with the IPFIX requirements. The routing device checks the NetFlow cache once per second and expires the flow in the following instances: 1. Transport is completed (TCP FIN or RST). 2. The flow cache has become full. 3. The inactive timer has expired after 15 seconds of traffic inactivity. This inactive timer is configurable. 4. The active timer has expired after 30 minutes of traffic activity. This active timer is configurable. Claise Expires û Mars 2003 [Page 13] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 3.4.7 Multicast (5.7) Total Compliance of the multicast support with the IPFIX requirements. 3.4.8 Ignore Port Copy (5.8) To be written. 3.5 Data Export (6) 3.5.1 Information Model (6.1) ôThe exporting process MUST be able to report the following attributes for each metered flowö, as defined in [IPFIX-REQ]: 1. IP version number: Upcoming Compliance (NetFlow will support IPV6) 2. source IP address: Total Compliance 3. destination IP address: Total Compliance 4. IP protocol type (TCP,UDP,ICMP,...) : Total Compliance 5. source TCP/UDP port number: Total Compliance 6. destination TCP/UDP port number: Total Compliance 7. input interface (ifIndex): Total Compliance 8. output interface (ifIndex): Total Compliance 9. packet counter: Total Compliance 10. byte counter: Total Compliance 11. in case of IPv4, Type of Service: Total Compliance 12. in case of IPv6, Flow Label: Upcoming Compliance 13. if BGP is supported at the observation point, BGP AS number: Total Compliance 14. if MPLS is supported at the observation point, MPLS label: Total Compliance 15. if DiffServ is supported at the observation point, DSCP: Partial Compliance 16. timestamp of the first packet of the flow: Total Compliance 17. timestamp of the last packet of the flow: Total Compliance 18. if sampling is used, sampling configuration: Total Compliance 19. unique identifier of the observation point: Total Compliance (the ifIndex) 20. unique identifier of the exporting process: Total Compliance (the IP address) ôThe exporting process SHOULD be able to report the following attributes for each metered flowö, as defined in [IPFIX-REQ]: Claise Expires û Mars 2003 [Page 14] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 21. multicast replication factor. Total Compliance ôThe exporting process MAY be able to report the following attributes for each metered flowö, as defined in [IPFIX-REQ]: 22. Time To Live: Extension required for total compliance 23. IP header flags: Extension required for total compliance 24. TCP header flags: Total Compliance 25. dropped packet counter at the observation point: Extension required for total compliance 26. fragmented packet counter: Extension required for total compliance 3.5.2 Data Model (6.2) ôThe data model MUST be extensibleö, as defined in [IPFIX-REQ]. Total compliance. ôThe data model used for exporting flow information MUST be flexible concerning the flow attributes contained in flow recordsö, as defined in [IPFIX-REQ]. Total compliance. ôThe Data Model SHOULD be independent of the underlying transport protocol, i.e. the data transferö, as defined in [IPFIX-REQ]. Total compliance. 3.5.3 Data Transfer (6.3) 3.5.3.1 Congestion Awareness (6.3.1) ôFor the data transfer, a congestion aware protocol MUST be supportedö, as defined in [IPFIX-REQ]. To be written. 3.5.3.2 Reliability (6.3.2) Total Compliance. A sequence ID exists per export packet so that the collecting process would know if it misses export packets or if packets reordering occurred in the network. 3.5.3.3 Security (6.3.3) Failed compliance for confidentiality, integrity and authenticity. Claise Expires û Mars 2003 [Page 15] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 3.5.4 Regular Reporting Interval (6.4) Total compliance. For long aging flows, the exporting process exports the flow records on regular basis, in order to: 1. report the flow records periodic accounting information to the collecting process 2. avoid counter wrapping This activity timeout is configurable 3.5.5 Notification on Specific Events (6.5) Failed compliance. 3.5.6 Anonymization (6.6) To be written. 3.6 Configuration (7) 3.6.1 Configuration of the Metering Process (7.1) Total Compliance. 3.6.2 Configuration of the Exporting Process (7.2) Total Compliance. 3.7 General Requirements Compliance (8) 3.7.1 Openness (8.1) Total Compliance. 3.7.2 Scalability Concerning the Number of Exporting Processes (8.2) Claise Expires û Mars 2003 [Page 16] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 ôData collection from hundreds of different exporting processes MUST be supported.ö, as defined in [IPFIX-REQ]. Total Compliance. ôThe collecting process MUST be able to distinguish several hundred exporting processes by their identifiers.ö, as defined in [IPFIX- REQ]. Total Compliance, the identifier being the IP address of the exporting process. 3.7.3 Several Collecting Processes (8.3) Total Compliance. The exporting process is able to export flow information to two different collecting process. 4. Security Considerations Security considerations for the IPFIX protocol are covered by the comparison against the specific Security requirements in the IPFIX requirements document [IPFIX-REQ] where they are specifically addressed by sections 6.3.3 and 10. The NetFlow flow record export protocol could be run on the top of IPSEC [IPSEC] to assure security. 5. References [IPFIX-REQ] J. Quittek et al., "Requirements for IP Flow Information Export", draft-ietf-ipfix-reqs-05.txt, work in progress, July 2002. [IPFIX-REQ6] J. Quittek et al., "Requirements for IP Flow Information Export", draft-ietf-ipfix-reqs-06.txt, work in progress, July 2002. [NETFLOW9] B. Claise et al., "Cisco Systems NetFlow Services Export Version 9", draft-bclaise-netflow-9-00.txt, work in progress, June 2002. [UDP] J. Postel, "User Datagram Protocol", RFC 768, August 1980 [TCP] "TRANSMISSION CONTROL PROTOCOL DARPA INTERNET PROGRAM Claise Expires û Mars 2003 [Page 17] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 PROTOCOL SPECIFICATION", RFC 793, September 1981 [SCTP] R. Stewart et al, "Stream Control Transmission Protocol", RFC 2960, October 2000 [IPSEC] Kent, S., "Security Architecture for the Internet Protocol", RFC 2401, Nov. 1998, 6. Author's Address Benoit Claise Cisco Systems De Kleetlaan 6a b1 1831 Diegem Belgium Phone: +32 2 704 5622 Email: bclaise@cisco.com 7. Full Copyright Statement Copyright (C) The Internet Society (2001). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING Claise Expires û Mars 2003 [Page 18] Evaluation Of NetFlow Version 9 Against IPFIX Requirements Sept. 2002 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Claise Expires û Mars 2003 [Page 19]