--- 1/draft-ietf-6man-spring-srv6-oam-07.txt 2020-10-30 22:13:11.481713861 -0700 +++ 2/draft-ietf-6man-spring-srv6-oam-08.txt 2020-10-30 22:13:11.529715078 -0700 @@ -1,48 +1,51 @@ - 6man Z. Ali Internet-Draft C. Filsfils Intended status: Standards Track Cisco Systems -Expires: January 27, 2021 S. Matsushima +Expires: May 3, 2021 S. Matsushima Softbank D. Voyer Bell Canada M. Chen Huawei - July 26, 2020 + October 30, 2020 Operations, Administration, and Maintenance (OAM) in Segment Routing Networks with IPv6 Data plane (SRv6) - draft-ietf-6man-spring-srv6-oam-07 + draft-ietf-6man-spring-srv6-oam-08 Abstract - This document describes how the existing IPv6 OAM mechanisms can be - used in an SRv6 network. The document also introduces enhancements - for OAM mechanisms for SRv6 networks. + This document describes how the existing IPv6 mechanisms for ping and + traceroute can be used in an SRv6 network. The document also + specifies the OAM flag in the Segment Routing Header (SRH) for + performing controllable and predictable flow sampling from segment + endpoints. In addition, the document describes how a centralized + monitoring system performs a path continuity check between any nodes + within an SRv6 domain. 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 January 27, 2021. + This Internet-Draft will expire on May 3, 2021. Copyright Notice Copyright (c) 2020 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 @@ -53,59 +56,66 @@ described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3 1.3. Terminology and Reference Topology . . . . . . . . . . . 3 2. OAM Mechanisms . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. O-flag in Segment Routing Header . . . . . . . . . . . . 5 - 2.1.1. O-flag Processing . . . . . . . . . . . . . . . . . . 5 + 2.1.1. O-flag Processing . . . . . . . . . . . . . . . . . . 6 2.2. OAM Operations . . . . . . . . . . . . . . . . . . . . . 7 - 3. Illustrations . . . . . . . . . . . . . . . . . . . . . . . . 7 + 3. Illustrations . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1. Ping in SRv6 Networks . . . . . . . . . . . . . . . . . . 8 3.1.1. Classic Ping . . . . . . . . . . . . . . . . . . . . 8 - 3.1.2. Pinging a SID . . . . . . . . . . . . . . . . . . . . 9 + 3.1.2. Pinging a SID . . . . . . . . . . . . . . . . . . . . 10 3.2. Traceroute . . . . . . . . . . . . . . . . . . . . . . . 10 - 3.2.1. Classic Traceroute . . . . . . . . . . . . . . . . . 10 + 3.2.1. Classic Traceroute . . . . . . . . . . . . . . . . . 11 3.2.2. Traceroute to a SID . . . . . . . . . . . . . . . . . 12 - 3.3. A Hybrid OAM Using O-flag . . . . . . . . . . . . . . . . 13 + 3.3. A Hybrid OAM Using O-flag . . . . . . . . . . . . . . . . 14 3.4. Monitoring of SRv6 Paths . . . . . . . . . . . . . . . . 16 - 4. Implementation Status . . . . . . . . . . . . . . . . . . . . 17 - 5. Security Considerations . . . . . . . . . . . . . . . . . . . 17 - 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 - 6.1. Segment Routing Header Flags . . . . . . . . . . . . . . 17 + 4. Implementation Status . . . . . . . . . . . . . . . . . . . . 18 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 18 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18 - 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 19 - 9.1. Normative References . . . . . . . . . . . . . . . . . . 19 - 9.2. Informative References . . . . . . . . . . . . . . . . . 19 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 + 9.1. Normative References . . . . . . . . . . . . . . . . . . 20 + 9.2. Informative References . . . . . . . . . . . . . . . . . 20 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 1. Introduction As Segment Routing with IPv6 data plane (SRv6) [RFC8402] simply adds a new type of Routing Extension Header, existing IPv6 OAM mechanisms can be used in an SRv6 network. This document describes how the existing IPv6 mechanisms for ping and trace route can be used in an - SRv6 network. + SRv6 network. This includes illustrations to pinging an SRv6 SID for + the SID connectivity checks and to validate the availability of a + SID. This also includes illustrations for tracerouting to an SRv6 + SID for hop-by-hop fault localization as well as path tracing to a + SID. The document also introduces enhancements for OAM mechanism for SRv6 - networks. Specifically, the document describes an OAM mechanism for - performing controllable and predictable flow sampling from segment - endpoints using, e.g., IP Flow Information Export (IPFIX) protocol + networks for performing controllable and predictable flow sampling + from segment endpoints using, e.g., IP Flow Information Export + (IPFIX) protocol [RFC7011]. Specifically, the document specifies + O-flag in SRH as a marking-bit in the user packets to trigger the + telemetry data collection and export at the segment endpoints. - [RFC7011]. The document also outlines how centralized OAM technique - in [RFC8403] can be extended for SRv6 to perform a path continuity - check between any nodes within an SRv6 domain from a centralized - monitoring system. + The document also outlines how centralized OAM technique in [RFC8403] + can be extended for SRv6 to perform a path continuity check between + any nodes within an SRv6 domain. Specifically, the document + illustrates how a centralized monitoring system can monitor arbitrary + SRv6 paths by creating the loopback probes that originates and + terminates at the centralized monitoring system. 1.1. Requirements Language 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], [RFC8174]. 1.2. Abbreviations The following abbreviations are used in this document: @@ -190,22 +200,22 @@ SID list but encoded in the SRH format where the rightmost SID in the SRH is the first SID and the leftmost SID in the SRH is the last SID. When referring to an SR policy in a high-level use-case, it is simpler to use the notation. When referring to an illustration of the detailed packet behavior, the (S3, S2, S1; SL) notation is more convenient. * (payload) represents the the payload of the packet. SRH[SL] represents the SID pointed by the SL field in the first - SRH. In our example SID list (S3, S2, S1; SL), SRH[2] represents - S1, SRH[1] represents S2 and SRH[0] represents S3. + SRH. In our example SID list (S3, S2, S1; SL), SRH(2) represents + S1, SRH(1) represents S2 and SRH(0) represents S3. 2. OAM Mechanisms This section defines OAM enhancement for the SRv6 networks. 2.1. O-flag in Segment Routing Header [RFC8754] describes the Segment Routing Header (SRH) and how SR capable nodes use it. The SRH contains an 8-bit "Flags" field. This document defines the following bit in the SRH.Flags to carry the @@ -299,26 +309,26 @@ Ping to a SID is used for SID connectivity checks and to validate the availability of a SID. Traceroute to a SID is used for hop-by-hop fault localization as well as path tracing to a SID. Section 3 illustrates the ICMPv6 based ping and the UDP based traceroute mechanisms for ping and traceroute to an SRv6 SID. Although this document only illustrates ICMP ping and UDP-based traceroute to an SRv6 SID, the procedures are equally applicable to other IPv6 OAM probing to an SRv6 SID (e.g., Bidirectional Forwarding Detection (BFD) [RFC5880], Seamless BFD (SBFD) [RFC7880], TWAMP Light and STAMP - probe message processing as described in - [I-D.gandhi-spring-twamp-srpm] and [I-D.gandhi-spring-stamp-srpm], - respectively, etc.). Specifically, as long as local configuration - allows the Upper-layer Header processing of the applicable OAM payload - for SRv6 SIDs, the existing IPv6 OAM techniques can be used to target - a probe to a (remote) SID. + probe message processing as described in [I-D.gandhi-spring-twamp- + srpm] and [I-D.gandhi-spring-stamp-srpm], respectively, etc.). + Specifically, as long as local configuration allows the Upper-layer + Header processing of the applicable OAM payload for SRv6 SIDs, the + existing IPv6 OAM techniques can be used to target a probe to a + (remote) SID. IPv6 OAM operations can be performed with the target SID in the IPv6 destination address without SRH or with SRH where the target SID is the last segment. In general, OAM operations to a target SID may not exercise all of its processing depending on its behavior definition. For example, ping to an END.X SID (refer [I-D.ietf-spring-srv6- network-programming]) at the target node only validates availability of the SID and does not validate switching to the correct outgoing interface. To exercise the behavior of a target SID, the OAM operation SHOULD construct the probe in a manner similar to a data @@ -786,24 +796,29 @@ 5. Security Considerations This document does not define any new protocol extensions and relies on existing procedures defined for ICMP. This document does not impose any additional security challenges to be considered beyond security considerations described in [RFC4884], [RFC4443], [RFC0792], and [RFC8754]. 6. IANA Considerations -6.1. Segment Routing Header Flags + This document requests that IANA allocate the following registrations + in the "Segment Routing Header Flags" sub-registry for the "Internet + Protocol Version 6 (IPv6) Parameters" registry maintained by IANA: - This I-D requests to IANA to allocate bit position 2, within the - "Segment Routing Header Flags" registry defined in [RFC8754]. + +-------+------------------------------+---------------+ + | Bit | Description | Reference | + +=======+==============================+===============+ + | 2 | O-flag | This document | + +-------+------------------------------+---------------+ 7. Acknowledgements The authors would like to thank Joel M. Halpern, Greg Mirsky, Bob Hinden, Loa Andersson, Gaurav Naik, Ketan Talaulikar and Haoyu Song for their review comments. 8. Contributors The following people have contributed to this document: @@ -864,41 +878,41 @@ [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, . 9.2. Informative References [I-D.gandhi-spring-stamp-srpm] Gandhi, R., Filsfils, C., Voyer, D., Chen, M., and B. - Janssens, "Performance Measurement Using STAMP for Segment - Routing Networks", draft-gandhi-spring-stamp-srpm-01 (work - in progress), June 2020. + Janssens, "Performance Measurement Using Simple TWAMP + (STAMP) for Segment Routing Networks", draft-gandhi- + spring-stamp-srpm-03 (work in progress), October 2020. [I-D.gandhi-spring-twamp-srpm] Gandhi, R., Filsfils, C., Voyer, D., Chen, M., and B. Janssens, "Performance Measurement Using TWAMP Light for Segment Routing Networks", draft-gandhi-spring-twamp- - srpm-09 (work in progress), June 2020. + srpm-11 (work in progress), October 2020. [I-D.ietf-spring-srv6-network-programming] Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., Matsushima, S., and Z. Li, "SRv6 Network Programming", - draft-ietf-spring-srv6-network-programming-16 (work in - progress), June 2020. + draft-ietf-spring-srv6-network-programming-24 (work in + progress), October 2020. [I-D.matsushima-spring-srv6-deployment-status] Matsushima, S., Filsfils, C., Ali, Z., Li, Z., and K. Rajaraman, "SRv6 Implementation and Deployment Status", - draft-matsushima-spring-srv6-deployment-status-07 (work in - progress), April 2020. + draft-matsushima-spring-srv6-deployment-status-08 (work in + progress), October 2020. [RFC0792] Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, DOI 10.17487/RFC0792, September 1981, . [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", STD 89, RFC 4443, DOI 10.17487/RFC4443, March 2006, .