IP flow information exchange L. Coene Working group Siemens Internet-Draft P. Conrad Expires: August 14, 2003 Temple University February 13, 2003 Reliable Server pool use in IP flow information exchange 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 obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." 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. This Internet-Draft will expire on August 14, 2003. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This document describes the applicability of the relialeble server pool architecture to the IP flow information exchange using Endpoint Name Resolution Protocol(ENRP) function of Rserpool only. Data exchange in IPFIX between the router and the datacollector can be using a limited retransmission protocol. Coene & Conrad Expires August 14, 2003 [Page 1] Internet-Draft Rspool applicability for IPFIX February 2003 1. INTRODUCTION Reliable server pooling provides protocols for providing higly available services. The services are located in pool of redundant servers and if a server fails, another server will take over. The only requirement put on these servers belonging to the pool is that if state is maintained by the server, this state must be transfered to the other server taking over. The mechanism for transfering this state information is NOT part of the Reliable server pooling architecture and/or protocols and must be provided by other protocols. The goal is to provide server based redundancy. Transport and network level redundancy are handle by the transport and network layer protcols. The application may choose to distribute its traffic over the servers of the pool conforming to a certain policy. The application wishing to make use of Rserpool protocols may use different transport layers(such as UDP, TCP and SCTP). However some transport layers may have restrictions build in in the way they might be operating in the Rserpool architecture and its protocols. 1.1 Scope The scope of this document is to explain the way that a minimal version of Reliable server pool protocols have to be used in order to provide a higly available service towards IP flow Information Exchange(IPFIX) protocols. 1.2 Terminology The terms are commonly identified in related work and can be found in the Aggregate Server Access Protocol and Endpoint Name Resolution Protocol Common Parameters document[RFCCOMM]. Coene & Conrad Expires August 14, 2003 [Page 2] Internet-Draft Rspool applicability for IPFIX February 2003 2. IPFIX using Rserpool 2.1 Architecture IP flow information is exchanged between observation points and collector points. The observation points may try to find out via the endpoint resolution protocol(ENRP) which collector point(s) are active. Both the observation and the collector point may have limitations for exchanging the information( observation point may have limited buffer space and collectors points may be overburdened with receiving lots of flow info from different observation points). The observation point will query the ENRP server for resolution of a particular collector pool name and ENRP will return to the observation point of list of 1 or more collector points. The observation point will use its own transport protocols(TCP, UDP, SCTP, PR-SCTP) for exchanging the IPFIX data between the observation point and the collection point. If a collection point would fail, then the observation point will send its data towards a different collector point, belonging to the same collector pool. Collector points will announce themselves to the ENRP server and will be monitored for their avialebility. The observation point will only query the ENRP server for server pool namer resolution. Coene & Conrad Expires August 14, 2003 [Page 3] Internet-Draft Rspool applicability for IPFIX February 2003 3. Transport protocols suitable for IPFIX The exchange of IP flow information data between a observation point and a collection point consists of massive ammounts of data. One collection point can service many observation points, therefore transport protocols must do congestion control(example: modifying the receive buffer space, thus reducing the incoming flow of data), so that the collection point is not overburdened by its collections points. Some data must arrive at the collectore while othr data migth arrive(if it get lost, no problem). The choice of relialeble or partial relialeble delivery has to be made by the observation point. This calls for a protocol that should have variable relialebility for the transport of its data, prefereably to be chosen by IPFIX protocols on a per-message base. PR-SCTP is the only know protocol which allows the choice of full, partial or no relialeble delivery of the message to its peer node. TCP will only allow full relialeble delivery, while UDP has only unrelialeble delivery and NO congestion control to speak of. Coene & Conrad Expires August 14, 2003 [Page 4] Internet-Draft Rspool applicability for IPFIX February 2003 4. Security considerations The protocols used in the Reliable server pool architecture only tries to increase the availability of the servers in the network. Rserpool protocols does not contain any protocol mechanisms which are directly related to user message authentication, integrity and confidentiality functions. For such features, it depends on the IPSEC protocols or on Transport Layer Security(TLS) protocols for its own security and on the architecture and/or security features of its user protocols. Rserpool architecture allows the use of different Transport protocols for its application and control data exchange. Those transport protocols may have mechanisms for reducing the risk of blind denial-of-service attacks and/or masquerade attacks. If such measures are required by the applications, then it is advised to check the SCTP applicability statement[RFC3057] for guidance on this issue. Coene & Conrad Expires August 14, 2003 [Page 5] Internet-Draft Rspool applicability for IPFIX February 2003 5. Acknowledgments The authors wish to thank X, Y and M. Stillman and many others for their invaluable comments. Coene & Conrad Expires August 14, 2003 [Page 6] Internet-Draft Rspool applicability for IPFIX February 2003 References [1] Tuexen, M., Stewart, R., Shore, M., Xie, Q., Ong, L., Loughney, J. and M. Stillman, "Requirements for Reliable Server Pooling", RFC 3237, January 2002. [2] Tuexen, M., Stewart, R., Shore, M., Xie, Q., Ong, L., Loughney, J. and M. Stillman, "Architecture for Reliable Server Pooling", Draft in progress , October 2002. [3] Stewart, R., Xie, Q., Stillman, M. and M. Tuexen, "Aggregate Server Access Protocol (ASAP)", Draft in progress , October 2002. [4] Xie, Q., Stewart, R. and M. Stillman, "Endpoint Name Resolution Protocol (ENRP)", Draft in progress , October 2002. [5] Stewart, R., Xie, Q., Stillman, M. and M. Tuexen, "Aggregate Server Access Protocol and Endpoint Name Resolution Protocol Common Parameters", Draft in progress , October 2002. [6] Conrad, P. and P. Lei, ""Services Provided By Reliable Server Pooling", Draft in progress , January 2003. [7] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L. and V. Paxson, ""Stream Control Transmission Protocol"", RFC 2960, October 2000. [8] Coene, L., ""Stream Control Transmission Protocol Applicability statement"", RFC 3257, April 2002. Authors' Addresses Lode Coene Siemens Atealaan 32 Herentals 2200 Belgium Phone: +32-14-252081 EMail: lode.coene@siemens.com Coene & Conrad Expires August 14, 2003 [Page 7] Internet-Draft Rspool applicability for IPFIX February 2003 Phil Conrad Temple University zzz zzzz zzzz USA Phone: zzzz EMail: zzzz Coene & Conrad Expires August 14, 2003 [Page 8] Internet-Draft Rspool applicability for IPFIX February 2003 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Full Copyright Statement Copyright (C) The Internet Society (2003). 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 assignees. 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 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION Coene & Conrad Expires August 14, 2003 [Page 9] Internet-Draft Rspool applicability for IPFIX February 2003 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Coene & Conrad Expires August 14, 2003 [Page 10]