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diff --git a/doc/rfc/rfc9160.txt b/doc/rfc/rfc9160.txt new file mode 100644 index 0000000..f5fb16b --- /dev/null +++ b/doc/rfc/rfc9160.txt @@ -0,0 +1,257 @@ + + + + +Internet Engineering Task Force (IETF) T. Graf +Request for Comments: 9160 Swisscom +Category: Informational December 2021 +ISSN: 2070-1721 + + + Export of MPLS Segment Routing Label Type Information in IP Flow + Information Export (IPFIX) + +Abstract + + This document introduces new IP Flow Information Export (IPFIX) code + points to identify which traffic is being forwarded based on which + MPLS control plane protocol is used within a Segment Routing domain. + In particular, this document defines five code points for the IPFIX + mplsTopLabelType Information Element for Path Computation Element + (PCE), IS-IS, OSPFv2, OSPFv3, and BGP MPLS Segment Routing + extensions. + +Status of This Memo + + This document is not an Internet Standards Track specification; it is + published for informational purposes. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Not all documents + approved by the IESG are candidates for any level of Internet + Standard; see Section 2 of RFC 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + https://www.rfc-editor.org/info/rfc9160. + +Copyright Notice + + Copyright (c) 2021 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 + (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. MPLS Segment Routing Top Label Type + 3. IANA Considerations + 4. Operational Considerations + 5. Security Considerations + 6. References + 6.1. Normative References + 6.2. Informative References + Acknowledgements + Author's Address + +1. Introduction + + Four routing protocol extensions -- OSPFv2 Extensions [RFC8665], + OSPFv3 Extensions [RFC8666], IS-IS Extensions [RFC8667], and BGP + Prefix Segment Identifiers (Prefix-SIDs) [RFC8669] -- and one Path + Computation Element Communication Protocol (PCEP) Extension [RFC8664] + have been defined to be able to propagate Segment Routing (SR) labels + for the MPLS data plane [RFC8660]. + + Also, [SR-Traffic-Accounting] describes how IP Flow Information + Export (IPFIX) [RFC7012] can be leveraged in dimensional data + modeling to account for traffic to MPLS SR label dimensions within a + Segment Routing domain. + + In [RFC7012], the Information Element (IE) mplsTopLabelType(46) + identifies which MPLS control plane protocol allocated the top-of- + stack label in the MPLS label stack. Per Section 7.2 of [RFC7012], + the "IPFIX MPLS label type (Value 46)" subregistry [IANA-IPFIX] was + created, where new MPLS label type entries should be added. This + document defines new code points to address typical use cases that + are discussed in Section 2. + +2. MPLS Segment Routing Top Label Type + + By introducing five new code points to the IPFIX IE + mplsTopLabelType(46) for Path Computation Element (PCE), IS-IS, + OSPFv2, OSPFv3, and BGP Prefix-SIDs, it is possible to identify which + traffic is being forwarded based upon which MPLS SR control plane + protocol is in use. + + A typical use case is to monitor MPLS control plane migrations from + LDP to IS-IS or OSPF Segment Routing. Such a migration can be done + node by node as described in Appendix A of [RFC8661]. + + Another use case is to monitor MPLS control plane migrations from + dynamic BGP labels [RFC8277] to BGP Prefix-SIDs [RFC8669]. For + example, the motivation for, and benefits of, such a migration in + large-scale data centers are described in [RFC8670]. + + Both use cases can be verified by using mplsTopLabelType(46), + mplsTopLabelIPv4Address(47), mplsTopLabelIPv6Address(140), + mplsTopLabelStackSection(70), and forwardingStatus(89) IEs to infer + + * how many packets are forwarded or dropped + + * if packets are dropped, for which reasons, and + + * the MPLS provider edge loopback address and label protocol + + By looking at the MPLS label value itself, it is not always clear to + which label protocol it belongs. This is because they may share the + same label allocation range. This is, for example, the case for IGP- + Adjacency SIDs, LDP, and dynamic BGP labels. + +3. IANA Considerations + + IANA has allocated the following code points in the "IPFIX MPLS label + type (Value 46)" subregistry within the "IPFIX Information Elements" + registry [RFC7012]. See [IANA-IPFIX]. + + +=======+================================+====================+ + | Value | Description | Reference | + +=======+================================+====================+ + | 6 | Path Computation Element | RFC 9160, RFC 8664 | + +-------+--------------------------------+--------------------+ + | 7 | OSPFv2 Segment Routing | RFC 9160, RFC 8665 | + +-------+--------------------------------+--------------------+ + | 8 | OSPFv3 Segment Routing | RFC 9160, RFC 8666 | + +-------+--------------------------------+--------------------+ + | 9 | IS-IS Segment Routing | RFC 9160, RFC 8667 | + +-------+--------------------------------+--------------------+ + | 10 | BGP Segment Routing Prefix-SID | RFC 9160, RFC 8669 | + +-------+--------------------------------+--------------------+ + + Table 1: Updates to "IPFIX MPLS label type (Value 46)" + Subregistry + + References to RFCs 4364, 4271, and 5036 have been added to the + "Reference" column in the "IPFIX MPLS label type (Value 46)" + subregistry [IANA-IPFIX] for code points 3, 4, and 5, respectively. + Previously, these references appeared in the "Additional Information" + column for mplsTopLabelType(46) in the "IPFIX Information Elements" + registry [IANA-IPFIX]. + +4. Operational Considerations + + In the IE mplsTopLabelType(46), BGP code point 4 refers to the label + value in the MP_REACH_NLRI path attribute described in Section 2 of + [RFC8277], while BGP Segment Routing Prefix-SID code point 10 + corresponds to the label index value in the Label-Index TLV described + in Section 3.1 of [RFC8669]. These values are thus used for those + distinct purposes. + +5. Security Considerations + + There exist no significant extra security considerations regarding + the allocation of these new IPFIX IEs as compared to [RFC7012]. + +6. References + +6.1. Normative References + + [RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model + for IP Flow Information Export (IPFIX)", RFC 7012, + DOI 10.17487/RFC7012, September 2013, + <https://www.rfc-editor.org/info/rfc7012>. + +6.2. Informative References + + [IANA-IPFIX] + IANA, "IPFIX MPLS label type (Value 46)", + <https://www.iana.org/assignments/ipfix/>. + + [RFC8277] Rosen, E., "Using BGP to Bind MPLS Labels to Address + Prefixes", RFC 8277, DOI 10.17487/RFC8277, October 2017, + <https://www.rfc-editor.org/info/rfc8277>. + + [RFC8660] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S., + Decraene, B., Litkowski, S., and R. Shakir, "Segment + Routing with the MPLS Data Plane", RFC 8660, + DOI 10.17487/RFC8660, December 2019, + <https://www.rfc-editor.org/info/rfc8660>. + + [RFC8661] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S., + Decraene, B., and S. Litkowski, "Segment Routing MPLS + Interworking with LDP", RFC 8661, DOI 10.17487/RFC8661, + December 2019, <https://www.rfc-editor.org/info/rfc8661>. + + [RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., + and J. Hardwick, "Path Computation Element Communication + Protocol (PCEP) Extensions for Segment Routing", RFC 8664, + DOI 10.17487/RFC8664, December 2019, + <https://www.rfc-editor.org/info/rfc8664>. + + [RFC8665] Psenak, P., Ed., Previdi, S., Ed., Filsfils, C., Gredler, + H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF + Extensions for Segment Routing", RFC 8665, + DOI 10.17487/RFC8665, December 2019, + <https://www.rfc-editor.org/info/rfc8665>. + + [RFC8666] Psenak, P., Ed. and S. Previdi, Ed., "OSPFv3 Extensions + for Segment Routing", RFC 8666, DOI 10.17487/RFC8666, + December 2019, <https://www.rfc-editor.org/info/rfc8666>. + + [RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., + Bashandy, A., Gredler, H., and B. Decraene, "IS-IS + Extensions for Segment Routing", RFC 8667, + DOI 10.17487/RFC8667, December 2019, + <https://www.rfc-editor.org/info/rfc8667>. + + [RFC8669] Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah, + A., and H. Gredler, "Segment Routing Prefix Segment + Identifier Extensions for BGP", RFC 8669, + DOI 10.17487/RFC8669, December 2019, + <https://www.rfc-editor.org/info/rfc8669>. + + [RFC8670] Filsfils, C., Ed., Previdi, S., Dawra, G., Aries, E., and + P. Lapukhov, "BGP Prefix Segment in Large-Scale Data + Centers", RFC 8670, DOI 10.17487/RFC8670, December 2019, + <https://www.rfc-editor.org/info/rfc8670>. + + [SR-Traffic-Accounting] + Ali, Z., Filsfils, C., Talaulikar, K., Sivabalan, S., + Horneffer, M., Raszuk, R., Litkowski, S., Voyer, D., + Morton, R., and G. Dawra, "Traffic Accounting in Segment + Routing Networks", Work in Progress, Internet-Draft, + draft-ali-spring-sr-traffic-accounting-06, 13 November + 2021, <https://datatracker.ietf.org/doc/html/draft-ali- + spring-sr-traffic-accounting-06>. + +Acknowledgements + + I would like to thank the IE doctors, Paul Aitken and Andrew Feren, + as well as Benoît Claise, Loa Andersson, Tianran Zhou, Pierre + François, Bruno Decraene, Paolo Lucente, Hannes Gredler, Ketan + Talaulikar, Sabrina Tanamal, Erik Auerswald, Sergey Fomin, Mohamed + Boucadair, Tom Petch, Qin Wu, and Matthias Arnold for their review + and valuable comments. Many thanks also to Robert Wilton for the AD + review. Thanks to Alvaro Retana, Éric Vyncke, and Benjamin Kaduk for + the IESG review. + +Author's Address + + Thomas Graf + Swisscom + Binzring 17 + CH-8045 Zürich + Switzerland + + Email: thomas.graf@swisscom.com |