opsawg Z. Li Internet-Draft China Mobile Intended status: Standards Track P. Aitken Expires: January 1, 2018 Brocade Communications Systems, Inc. June 30, 2017 Extended Length Message Support for IP Flow Information Export (IPFIX) draft-li-opsawg-ipfix-extended-message-00 Abstract The specification of the IP Flow Information Export (IPFIX) Protocol [RFC7011] defines an IPFIX Message length of 16 bits. As new Information Elements (IEs) are introduced in IPFIX to export long information, such as the BGP community information [I-D.ietf-opsawg-ipfix-bgp-community], an IPFIX Message no longer has sufficient space to fit all the information of a specific flow. This document updates the IPFIX specification by extending the IPFIX Message length from 16 bits to 32 bits. For backwards compatibility, a new version of IPFIX (i.e., 11) is introduced to support the 32-bit Message length. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on January 1, 2018. Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of Li & Aitken Expires January 1, 2018 [Page 1] Internet-Draft Extended Length Message Support for IPFIX June 2017 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. IPFIX Extended Length Message . . . . . . . . . . . . . . . . 3 3.1. IPFIX Extended Length Message Header . . . . . . . . . . 3 3.2. IPFIX Extended Length Set Header . . . . . . . . . . . . 3 3.3. IPFIX Extended Variable-Length IE . . . . . . . . . . . . 4 4. Transport Protocol Considerations . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . 5 8.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction The IP Flow Information Export (IPFIX) Protocol [RFC7011] provides network administrators with traffic flow information using the Information Elements (IEs) defined in IANA's IPFIX registry [IANA-IPFIX]. [RFC7011] specifies an IPFIX Message length of 16 bits. As new IEs are introduced in IPFIX to export long information, such as the BGP community information [I-D.ietf-opsawg-ipfix-bgp-community], one IPFIX Message no longer has sufficient space to fit all the information of a specific flow. The maximum IPFIX message size needs to be extended beyond 65535 octets. This document updates the IPFIX specification by extending the IPFIX Message length from 16 bits to 32 bits, which means the maximum IPFIX message size is 4 giga bytes. For backwards compatibility, a new version of IPFIX (i.e., 11) is introduced to support the 32-bit Message length. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Li & Aitken Expires January 1, 2018 [Page 2] Internet-Draft Extended Length Message Support for IPFIX June 2017 3. IPFIX Extended Length Message The goal of this document is to allow the export of IPFIX messages up to 4294967295 (4 giga) octets to satisfy the two situations that may result in the IPFIX message beyond 65535 octets. One is the IPFIX message consisting of many small fields where each field is 8-bits or 16-bits long. The other one is the IPFIX message consisting of at least one IE which is longer than 65535 octets, such as the IEs defined in [I-D.ietf-opsawg-ipfix-bgp-community]. To satisfy the two situations, this document extends the following length fields to 32 bits: the Length field in the IPFIX Message Header, the Length field in the Set Header and the Length field in the variable-length IE. 3.1. IPFIX Extended Length Message Header The IPFIX Message Header with a 32 bits length field is called the IPFIX Extended Length Message Header, whose format is shown in Figure 1. The version number MUST be 11. The length field is 32-bits long. The meanings and other specifications of the fields in the Extended Length Message Header are in accordance with [RFC7011]. Please refer to Figure F in [RFC7011]. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Version Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Export Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Observation Domain ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: IPFIX Extended Length Message Header Format 3.2. IPFIX Extended Length Set Header The IPFIX Set Header with a 32 bits length field is called the IPFIX Extended Length Set Header, whose format is shown in Figure 2. The meanings and other specifications of the fields in the Extended Length Set Header are in accordance with [RFC7011]. Please refer to Figure I in [RFC7011]. Li & Aitken Expires January 1, 2018 [Page 3] Internet-Draft Extended Length Message Support for IPFIX June 2017 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Extended Length Set Header Format 3.3. IPFIX Extended Variable-Length IE The Extended Variable-Length IE allows export of variable-length IEs with size greater than or equal to 65535 octets, the length field of which is extended to 32 bits as shown in Figure 3. The meanings and other specifications of the fields in the Extended Variable-Length IE are in accordance with [RFC7011]. Please refer to Figure S in [RFC7011]. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+ | 255 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length (0 to 4294967295) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IE | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... continuing as needed | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Extended Variable-Length IE 4. Transport Protocol Considerations As per section 10 of RFC7011, the IPFIX Protocol is transport protocol independent. SCTP [RFC4960] using the Partially Reliable SCTP (PR-SCTP) extension as specified in [RFC3758] MUST be implemented by all compliant implementations. UDP [RFC768] MAY also be implemented by compliant implementations. TCP [RFC793] MAY also be implemented by compliant implementations. The Collecting Process of a compliant implementation supporting IPFIX Extended Length Message MUST be able to handle IPFIX Message lengths of up to 4294967295 octets. Li & Aitken Expires January 1, 2018 [Page 4] Internet-Draft Extended Length Message Support for IPFIX June 2017 5. Security Considerations This extension to IPFIX does not change IPFIX's underlying security issues, please refer to RFC7011. 6. IANA Considerations A new IPFIX Version Number value of 11 is reserved in IANA's IPFIX registry [IANA-IPFIX] for the IPFIX Extended Length Message specified in this document. 7. Acknowledgements The authors would like to thank Ignas Bagdonas and Stewart Bryant for their constructive discussion. 8. References 8.1. Normative References [IANA-IPFIX] IANA, "IPFIX Information Elements registry", . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, DOI 10.17487/RFC7011, September 2013, . 8.2. Informative References [I-D.ietf-opsawg-ipfix-bgp-community] Li, Z., Gu, R., and J. Dong, "Export BGP community information in IP Flow Information Export (IPFIX)", draft- ietf-opsawg-ipfix-bgp-community-02 (work in progress), June 2017. [RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P. Conrad, "Stream Control Transmission Protocol (SCTP) Partial Reliability Extension", RFC 3758, DOI 10.17487/RFC3758, May 2004, . Li & Aitken Expires January 1, 2018 [Page 5] Internet-Draft Extended Length Message Support for IPFIX June 2017 [RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol", RFC 4960, DOI 10.17487/RFC4960, September 2007, . Authors' Addresses Zhenqiang Li China Mobile 32 Xuanwumen West Ave, Xicheng District Beijing 100053 China Email: li_zhenqiang@hotmail.com Paul Aitken Brocade Communications Systems, Inc. 19a Canning Street, Level 3 Edinburgh, Scotland EH3 8EG United Kingdom Email: paitken@brocade.com Li & Aitken Expires January 1, 2018 [Page 6]