OPSAWG M. Boucadair Internet-Draft Orange Intended status: Standards Track T. Reddy.K Expires: 12 November 2023 Nokia 11 May 2023 Export of UDP Options Information in IP Flow Information Export (IPFIX) draft-boucadair-opsawg-tsvwg-udp-ipfix-05 Abstract This document specifies new IP Flow Information Export (IPFIX) Information Elements for UDP options. Discussion Venues This note is to be removed before publishing as an RFC. Discussion of this document takes place on the Operations and Management Area Working Group Working Group mailing list (opsawg@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/opsawg/. Source for this draft and an issue tracker can be found at https://github.com/boucadair/udp-ipfix. 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 https://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 12 November 2023. Copyright Notice Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved. Boucadair & Reddy.K Expires 12 November 2023 [Page 1] Internet-Draft IPFIX IE for UDP Options May 2023 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions and Definitions . . . . . . . . . . . . . . . . . 2 3. UDP Options at a Glance . . . . . . . . . . . . . . . . . . . 3 4. New UDP IPFIX Information Elements . . . . . . . . . . . . . 4 4.1. udpOptions . . . . . . . . . . . . . . . . . . . . . . . 4 4.2. udpExpOptionExID . . . . . . . . . . . . . . . . . . . . 4 4.3. udpUnsafeExpOptionExID . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . 7 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction IP Flow Information Export (IPFIX) [RFC7011] is a protocol that is widely deployed in operators networks for traffic management purposes. The protocol specifies the encoding of a set of basic data types and how the various Information Elements (IEs) are transmitted. In order to support the export of new flow-related measurement data, new IEs can be defined and registered in a dedicated IANA registry [IANA-IPFIX] for interoperability. This document specifies new IPFIX Information Elements for UDP options (Section 6). A brief overview of UDP option is provided in Section 3. 2. Conventions and Definitions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. Boucadair & Reddy.K Expires 12 November 2023 [Page 2] Internet-Draft IPFIX IE for UDP Options May 2023 This document uses the terms defined in Section 3 of [I-D.ietf-tsvwg-udp-options] and [RFC7011]. 3. UDP Options at a Glance UDP [RFC0768] does not support an extension mechanism similar to the options supported by other transport protocols, such as TCP [RFC9293], SCTP [RFC9260], or DCCP [RFC4340]. Such a mechanism can be useful for various applications, e.g., discover a path MTU or share timestamps. To fill that void, [I-D.ietf-tsvwg-udp-options] extends UDP with a mechanism to insert extensions in datagrams. To do so, and unlike the conventional approach that relies upon transport headers, [I-D.ietf-tsvwg-udp-options] uses trailers. Concretely, UDP options are placed in the surplus area (that is, the area of an IP payload that follows a UDP packet). See Figure 1. An example of the use of UDP options is described in [I-D.ietf-tsvwg-udp-options-dplpmtud]. IP transport payload <-------------------------------------------------> +--------+---------+----------------------+------------------+ | IP Hdr | UDP Hdr | UDP user data | surplus area | +--------+---------+----------------------+------------------+ <------------------------------> UDP Length Figure 1: Surplus Area Section 4.1 introduces a new IE to export the observed UDP options. Options indicated by Kind values in the range 0-191 are called SAFE options because they do not alter the UDP data payload. Such options can be silently ignored by receivers without affecting the meaning of the UDP user data (Section 9 of [I-D.ietf-tsvwg-udp-options]). Options indicated by Kind values in the range 192-255 are called UNSAFE options. Such options are not safe to ignore (Section 10 of [I-D.ietf-tsvwg-udp-options]). [I-D.ietf-tsvwg-udp-options] reserves two options for experiements: the Experimental option (EXP, Kind=127) for SAFE options and the UNSAFE Experimental option (UEXP, Kind=254). For both options, Experimental ID (ExIDs) are used to differentiate concurrent use of these options. Known ExIDs are expected to be registered within IANA. Section 4.2 specifies a new IPFIX IE to export observed ExIDs in the EXP options. Also, Section 4.3 specifies a new IPFIX to export observed ExIDs in the UEXP options. Only 16-bits ExIDs are supported. Boucadair & Reddy.K Expires 12 November 2023 [Page 3] Internet-Draft IPFIX IE for UDP Options May 2023 This document does not intend to elaborate operational guidance/ implications of UDP options. The document focuses exclusively on exporting observed UDP options in datagrams. The motivation for exporting such data is similar to the one for exporting TCP options (tcpOptions) or IPv6 Extension Headers (ipv6ExtensionHeaders). 4. New UDP IPFIX Information Elements 4.1. udpOptions Name: udpOptions ElementID: TBD1 Description: Observed UDP options of a Flow. The information is encoded in a set of bit fields. To cover the 0-255 kind range, up to 255 flags can be set in the value field. The encoding specified in Section 6.2 of [RFC7011] is followed whenever fewer octets are needed to report observed UDP options. For example, if only option kinds =<32 are observed, then the value can be encoded as unsigned32, or if only option kinds =<63 are observed, then the value can be encoded as unsigned64. Abstract Data Type: unsigned Data Type Semantics: flags Additional Information: See the assigned UDP options in the "UDP Option Kind Numbers" registry at URL_IANA_UDP_OPTIONS. See [I-D.ietf-tsvwg-udp-options] for more details about UDP options. Reference: This-Document 4.2. udpExpOptionExID Name: udpExpExID ElementID: TBD2 Description: Observed Expermients ID (ExIDs) in the Experimental option (EXP, Kind=127). The information is encoded in a set of 16-bit fields. Each 16-bit field carries the observed ExID in an EXP option. Boucadair & Reddy.K Expires 12 November 2023 [Page 4] Internet-Draft IPFIX IE for UDP Options May 2023 Abstract Data Type: octetArray Data Type Semantics: identifier Additional Information: See the assignments in the "UDP Experimental Option Experiment Identifiers (UDP ExIDs)" registry at URL_IANA_UDP_ExIDs. See [I-D.ietf-tsvwg-udp-options] for more details about ExIDs. Reference: This-Document 4.3. udpUnsafeExpOptionExID Name: udpUnsafeExpOptionExID ElementID: TBD3 Description: Observed Expermients ID (ExIDs) in the UNSAFE Experimental option (UEXP, Kind=254). The information is encoded in a set of 16-bit fields. Each 16-bit field carries the observed ExID in an UEXP option. Abstract Data Type: octetArray Data Type Semantics: identifier Additional Information: See the assignments in the "UDP Experimental Option Experiment Identifiers (UDP ExIDs)" registry at URL_IANA_UDP_ExIDs. See [I-D.ietf-tsvwg-udp-options] for more details about ExIDs. Reference: This-Document 5. Security Considerations This document does not introduce new security considerations other than those already discussed in [RFC7012]. The reader may refer to Section 22 of [I-D.ietf-tsvwg-udp-options] for the security considerations related to UDP options. Boucadair & Reddy.K Expires 12 November 2023 [Page 5] Internet-Draft IPFIX IE for UDP Options May 2023 6. IANA Considerations This document requests IANA to add the following new IEs to the IANA registry entitled "IP Flow Information Export (IPFIX) Entities" [IANA-IPFIX]: +=======+========================+==============================+ | Value | Name | Reference | +=======+========================+==============================+ | TBD1 | udpOptions | Section 4.1 of This-Document | +-------+------------------------+------------------------------+ | TBD2 | udpExpOptionExID | Section 4.2 of This-Document | +-------+------------------------+------------------------------+ | TBD3 | udpUnsafeExpOptionExID | Section 4.3 of This-Document | +-------+------------------------+------------------------------+ Table 1: New IPFIX Information Elements 7. References 7.1. Normative References [I-D.ietf-tsvwg-udp-options] Touch, J. D., "Transport Options for UDP", Work in Progress, Internet-Draft, draft-ietf-tsvwg-udp-options-20, 27 March 2023, . [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, . [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, . [RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model for IP Flow Information Export (IPFIX)", RFC 7012, DOI 10.17487/RFC7012, September 2013, . Boucadair & Reddy.K Expires 12 November 2023 [Page 6] Internet-Draft IPFIX IE for UDP Options May 2023 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 7.2. Informative References [I-D.ietf-tsvwg-udp-options-dplpmtud] Fairhurst, G. and T. Jones, "Datagram PLPMTUD for UDP Options", Work in Progress, Internet-Draft, draft-ietf- tsvwg-udp-options-dplpmtud-07, 6 April 2023, . [IANA-IPFIX] "IP Flow Information Export (IPFIX) Entities", n.d., . [RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram Congestion Control Protocol (DCCP)", RFC 4340, DOI 10.17487/RFC4340, March 2006, . [RFC9260] Stewart, R., Tüxen, M., and K. Nielsen, "Stream Control Transmission Protocol", RFC 9260, DOI 10.17487/RFC9260, June 2022, . [RFC9293] Eddy, W., Ed., "Transmission Control Protocol (TCP)", STD 7, RFC 9293, DOI 10.17487/RFC9293, August 2022, . Acknowledgments Thanks to Benoît Claise for the discussion on the ordering of IPFIX IEs. Authors' Addresses Mohamed Boucadair Orange 35000 Rennes France Email: mohamed.boucadair@orange.com Tirumaleswar Reddy.K Nokia India Email: kondtir@gmail.com Boucadair & Reddy.K Expires 12 November 2023 [Page 7]