Internet DRAFT - draft-ietf-opsawg-ipfix-mpls-sr-label-type
draft-ietf-opsawg-ipfix-mpls-sr-label-type
Network Working Group T. Graf
Internet-Draft Swisscom
Intended status: Informational 18 September 2021
Expires: 22 March 2022
Export of MPLS Segment Routing Label Type Information in
IP Flow Information Export (IPFIX)
draft-ietf-opsawg-ipfix-mpls-sr-label-type-11
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 used within a Segment Routing domain. In
particular, this document defines five code points for the IPFIX
mplsTopLabelType Information Element for PCE, IS-IS, OSPFv2, OSPFv3,
and BGP MPLS Segment Routing extensions.
Status of This Memo
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This Internet-Draft will expire on 22 March 2022.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Internet-Draft IPFIX MPLS Segment Routing Information September 2021
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. MPLS Segment Routing Top Label Type . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
4. Operational Considerations . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
Four routing protocol extensions, OSPFv2 Extensions [RFC8665], OSPFv3
Extensions [RFC8666], IS-IS Extensions [RFC8667], 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, [I-D.ali-spring-sr-traffic-accounting] describes how IP Flow
Information Export [RFC7012] can be leveraged in dimensional data
modelling to account 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. Section 7.2 of [RFC7012]
creates the "IPFIX MPLS label type (Value 46)" subregistry
[IANA-IPFIX] where MPLS label type should be added. This document
defines new code points to address typical use cases that are
discussed in Section 2.
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2. MPLS Segment Routing Top Label Type
By introducing five new code points to the IPFIX IE
mplsTopLabelType(46) for PCE, IS-IS, OSPFv2, OSPFv3 and BGP Prefix-
SID, 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 and benefits for 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 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 as
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
This document requests IANA to allocate the following code points in
the existing subregistry "IPFIX MPLS label type (Value 46)" under the
"IPFIX Information Elements" registry [RFC7012] available at
[IANA-IPFIX].
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+-------+--------------------------------+----------------------+
| Value | Description | Reference |
+-------+--------------------------------+----------------------+
| TBD1 | Path Computation Element | [RFC-to-be], RFC8664 |
+-------+--------------------------------+----------------------+
| TBD2 | OSPFv2 Segment Routing | [RFC-to-be], RFC8665 |
+-------+--------------------------------+----------------------+
| TBD3 | OSPFv3 Segment Routing | [RFC-to-be], RFC8666 |
+-------+--------------------------------+----------------------+
| TBD4 | IS-IS Segment Routing | [RFC-to-be], RFC8667 |
+-------+--------------------------------+----------------------+
| TBD5 | BGP Segment Routing Prefix-SID | [RFC-to-be], RFC8669 |
+-------+--------------------------------+----------------------+
Table 1: Updates to "IPFIX MPLS label type (Value 46)" subregistry
Note to the RFC-Editor:
* Please replace TBD1 - TBD5 with the values allocated by IANA
* Please replace the [RFC-to-be] with the RFC number assigned to
this document
Note IANA:
* Suggest to move the existing RFC references in the additional
information column of IE mplsTopLabelType(46) to reference column
for codepoint 3, 4 and 5.
4. Operational Considerations
In the IE mplsTopLabelType(46), the BGP code point 4 refers to the
label value in MP_REACH_NLRI path attribute described in Section 2 of
[RFC8277], while the BGP Segment Routing Prefix-SID code point TBD5
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 exists no significant extra security considerations regarding
the allocation of these new IPFIX IEs compared to [RFC7012].
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6. Acknowledgements
I would like to thank the IE doctors, Paul Aitken and Andrew Feren,
as well Benoit Claise, Loa Andersson, Tianran Zhou, Pierre Francois,
Bruno Decreane, 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, Eric Vyncke and Benjamin Kaduk for the IESG
review.
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", Work in
Progress, Internet-Draft, draft-ali-spring-sr-traffic-
accounting-05, 12 April 2021,
<https://www.ietf.org/archive/id/draft-ali-spring-sr-
traffic-accounting-05.txt>.
[IANA-IPFIX]
"IANA, IPFIX MPLS label type (Value 46)",
<https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-
mpls-label-type>.
[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>.
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[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>.
Author's Address
Thomas Graf
Swisscom
Binzring 17
CH-8045 Zurich
Switzerland
Email: thomas.graf@swisscom.com
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