Network Working Group                                            T. Graf
Internet-Draft                                                  Swisscom
Intended status: Standards Track                          April 26, 2020
Expires: October 28, 2020


        Export of MPLS Segment Routing Label Type Information in
                   IP Flow Information Export (IPFIX)
                draft-tgraf-ipfix-mpls-sr-label-type-04

Abstract

   This document introduces additional code points in the
   mplsTopLabelType Information Element for IS-IS, OSPFv2, OSPFv3 MPLS
   Segment Routing (SR) extensions and a new SID type element to enable
   Segment Routing label and segment type information in IP Flow
   Information Export (IPFIX).

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   the Trust Legal Provisions and are provided without warranty as
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  MPLS Segment Routing Top Label Type . . . . . . . . . . . . .   2
   3.  Segment Routing Segment Identifier Type . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   5
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Besides BGP-4 [RFC8277], LDP [RFC5036] and BGP VPN [RFC4364], three
   new routing-protocols, OSPFv2 Extensions [RFC8665], OSPFv3 Extensions
   [RFC8666] and IS-IS Extensions [RFC8667] have been added to the list
   of routing-protocols able to propagate Segment Routing labels for the
   MPLS dataplane [RFC8660].

   Traffic Accounting in Segment Routing Networks
   [I-D.ali-spring-sr-traffic-accounting] describes how IPFIX can be
   leveraged to account traffic to MPLS Segment Routing label dimensions
   within a Segment Routing domain.

   In the Information Model for IP Flow Information Export IPFIX
   [RFC7012], the information element #46 mplsTopLabelType describes
   which MPLS control plane protocol allocated the top-of-stack label in
   the MPLS label stack.  RFC 7012 section 7.2 [RFC7012] describes the
   IANA Information Element #46 SubRegistry [IANA-IPFIX-IE46] where new
   code points should be added.

2.  MPLS Segment Routing Top Label Type

   By introducing three new code points to information element #46
   mplsTopLabelType for IS-IS, OSPFv2 and OSPFv3, when Segment Routing
   with one of these three routing protocols is deployed, we get insight
   into which traffic is being forwarded based on which MPLS control
   plane protocol.

   A typical use case scenario is to monitor MPLS control plane
   migrations from LDP to IS-IS or OSPF.  By looking at the MPLS label
   value itself, it is not always clear as to which label protocol it
   belongs, since they could potentially share the same label allocation
   range.  This is the case for IGP-Adjacency SID's and LDP as an
   example.



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3.  Segment Routing Segment Identifier Type

   The introduction of a new Information Element called SrSidType, which
   contains the Segment Routing Segment Identifier type according to
   Segment Routing Architecture [RFC8402], allows the Segment Routing
   forwarding behaviour to be exported in IPFIX.

   A typical use case scenario is to monitor the forwarding behaviour
   when Topology Independent Fast Reroute
   [I-D.ietf-rtgwg-segment-routing-ti-lfa] or micro loop avoidance
   [I-D.bashandy-rtgwg-segment-routing-uloop] tunnel traffic with IGP-
   Adjacency Segment SID's or when ECMP load balancing should occur with
   Anycast-SID's.

4.  IANA Considerations

   This document specifies three additional code points for IS-IS, OSPv2
   and OSPFv3 Segment Routing extension in the existing sub-registry
   "IPFIX MPLS label type (Value 46)" of the "IPFIX Information
   Elements" and one new "IPFIX Information Element" with a new sub-
   registry in the "IP Flow Information Export (IPFIX) Entities" name
   space.

            ----------------------------------------------
            | Value|       Description       | Reference |
            |--------------------------------------------|
            | TBD1 | OSPFv2 Segment Routing  |  RFC8665  |
            |--------------------------------------------|
            | TBD2 | OSPFv3 Segment Routing  |  RFC8666  |
            |--------------------------------------------|
            | TBD3 | IS-IS Segment Routing   |  RFC8667  |
            ----------------------------------------------

      Figure 1: Updates to "IPFIX Information Element #46" SubRegistry

















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    --------------------------------------------------------------------
    |ElementID|  Name   |Abstract |Data Type |  Description  |Reference|
    |         |         |Data Type|Semantics |               |         |
    |------------------------------------------------------------------|
    |  TBD4   |SrSidType|unsigned8|identifier|This field     | RFC8402 |
    |         |         |         |          |identifies the |         |
    |         |         |         |          |Segment Routing|         |
    |         |         |         |          |Identifier Type|         |
    |         |         |         |          |of the MPLS    |         |
    |         |         |         |          |top-of-stack   |         |
    |         |         |         |          |label. SID     |         |
    |         |         |         |          |types for this |         |
    |         |         |         |          |field are      |         |
    |         |         |         |          |listed in the  |         |
    |         |         |         |          |SR SID type    |         |
    |         |         |         |          |registry.      |         |
    --------------------------------------------------------------------

    Figure 2: New "IPFIX Information Element #TBD4"

              -----------------------------------------
              | Value |  Description      | Reference |
              |---------------------------------------|
              | TBD5  | Unknown SID Type  |  RFC8402  |
              |---------------------------------------|
              | TBD6  | Prefix-SID        |  RFC8402  |
              |---------------------------------------|
              | TBD7  | Node-SID          |  RFC8402  |
              |---------------------------------------|
              | TBD8  | Anycast-SID       |  RFC8402  |
              |---------------------------------------|
              | TBD9  | Adjacency-SID     |  RFC8402  |
              |---------------------------------------|
              | TBD10 | LAN-Adjacency-SID |  RFC8402  |
              |---------------------------------------|
              | TBD11 | PeerNode-SID      |  RFC8402  |
              |---------------------------------------|
              | TBD12 | PeerAdj-SID       |  RFC8402  |
              |---------------------------------------|
              | TBD13 | PeerSet-SID       |  RFC8402  |
              |---------------------------------------|
              | TBD14 | Binding-SID       |  RFC8402  |
              -----------------------------------------

        Figure 3: New "IPFIX Information Element #TBD4" SubRegistry






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5.  Security Considerations

   The same security considerations apply as for the IPFIX Protocol
   RFC7012 [RFC7012].

6.  Acknowledgements

   I would like to thank Paul Aitken, Loa Andersson, Tianran Zhou,
   Pierre Francois, Bruno Decreane and Paolo Lucente for their review
   and valuable comments.

7.  References

7.1.  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>.

7.2.  Informative References

   [I-D.ali-spring-sr-traffic-accounting]
              Filsfils, C., Talaulikar, K., Sivabalan, S., Horneffer,
              M., Raszuk, R., Litkowski, S., Voyer, D., and R. Morton,
              "Traffic Accounting in Segment Routing Networks", draft-
              ali-spring-sr-traffic-accounting-04 (work in progress),
              February 2020.

   [I-D.bashandy-rtgwg-segment-routing-uloop]
              Bashandy, A., Filsfils, C., Litkowski, S., Decraene, B.,
              Francois, P., and P. Psenak, "Loop avoidance using Segment
              Routing", draft-bashandy-rtgwg-segment-routing-uloop-08
              (work in progress), January 2020.

   [I-D.ietf-rtgwg-segment-routing-ti-lfa]
              Litkowski, S., Bashandy, A., Filsfils, C., Decraene, B.,
              Francois, P., Voyer, D., Clad, F., and P. Camarillo,
              "Topology Independent Fast Reroute using Segment Routing",
              draft-ietf-rtgwg-segment-routing-ti-lfa-03 (work in
              progress), March 2020.

   [IANA-IPFIX-IE46]
              "IANA IP Flow Information Export (IPFIX) Information
              Element #46 SubRegistry",
              <https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-
              mpls-label-type>.




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   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/info/rfc4364>.

   [RFC5036]  Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed.,
              "LDP Specification", RFC 5036, DOI 10.17487/RFC5036,
              October 2007, <https://www.rfc-editor.org/info/rfc5036>.

   [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>.

   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.

   [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>.

   [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>.

Author's Address

   Thomas Graf
   Swisscom
   Binzring 17
   Zurich  8045
   Switzerland

   Email: thomas.graf@swisscom.com



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