SPRING C. Filsfils, Ed.
Internet-Draft F. Clad, Ed.
Intended status: Informational K. Talaulikar
Expires: November 16, 2020 Cisco Systems
May 15, 2020
SR-MPLS Data Plane with IPv6 Control Plane
draft-filsfils-spring-sr-mpls-ipv6-control-plane-01
Abstract
This document reminds the existence of the "Segment Routing (SR) MPLS
data-plane with IPv6 control-plane" solution that is mature from a
standardization, productization and commercial deployment viewpoint.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Context . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Reference diagram . . . . . . . . . . . . . . . . . . . . . . 3
4. Packet processing . . . . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
7. Informative References . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
This document reminds the existence of the "Segment Routing (SR) MPLS
dataplane with IPv6 control-plane". This solution is mature from a
standardization, productization and commercial deployment viewpoint.
Other proposed source routing solutions with MPLS-like label lookup
or mapping ids should list all their data-plane and control-plane
differences with respect to this mature solution and should justify
these differences with genuine benefits not available in the mature
solution described in this document and others referenced here that
are published by the SPRING and MPLS WGs.
2. Context
This is an existing solution.
o Mature IETF standardization
o Mature productization
o Commercially deployed
The IETF standardization references are:
o Architecture:
* Segment Routing [RFC8402]
o Data-plane:
* Homogenous MPLS deployment: [RFC8660]
* Hopping over IP-only parts of network: [RFC8663]
o Control-plane:
* IS-IS: [RFC8667]
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* OSPFv3: [RFC8666]
* BGP: [RFC4364]
* BGP-LS: [I-D.ietf-idr-bgp-ls-segment-routing-ext]
* SR Policy headend: [I-D.ietf-spring-segment-routing-policy]
o Service programming: [I-D.ietf-spring-sr-service-programming]
o OAM: [RFC8287]
3. Reference diagram
+--------------------------------------------------------------+
| +-------------------+ +-------------------+ |
| | | | | |
| | +-+-+ +-+-+ | |
| | |121| |231| | |
| | +-+-+ +-+-+ | |
| | +---+ | | +---+ | |
| | |PE1| | | |PE2| | |
| | +---+ +-+-+ +-+-+ +---+ | |
| | |122| |232| | |
| | +-+-+ +-+-+ | |
| | (MPLS island 1) | | (MPLS island 2) | |
| +-------------------+ (IPv6 network) +-------------------+ |
+--------------------------------------------------------------+
Figure 1: IPv6 network with SR-MPLS islands
o Single IGP domain, IPv6 only
* PE1 is configured with a loopback IP address 2001:db8::1
* PE2 is configured with a loopback IP address 2001:db8::2
* Each other node k is configured with a loopback IP address
2001:db8::k
o 2 SR-MPLS islands running with an IPv6 control plane
* PE1 is configured with a Prefix-SID 16001 associated with
2001:db8::1
* PE2 is configured with a Prefix-SID 16002 associated with
2001:db8::2
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4. Packet processing
+------------------------------------------------------------+
| +-------------------+ +-------------------+ |
| | | | | |
| | +-+-+ +-+-+ | |
| | +---->+121+----->------+231+-----+ | |
| | | +-+-+ +-+-+ | | |
| | +---+ | | | | +---+ | |
A +-----+PE1+-----+ | | +---->+PE2+-----> B
| | +---+ +-+-+ +-+-+ +---+ | |
| | |122| |232| | |
| | +-+-+ +-+-+ | |
| | (MPLS island 1) | | (MPLS island 2) | |
| +-------------------+ (IPv6 network) +-------------------+ |
+------------------------------------------------------------+
+----------+ +----------+ +--------------+ +----------+ +----------+
| IP4(A,B) | | 16002 | |IP6( | | 16002 | | IP4(A,B) |
+----------+ +----------+ |2001:db8::121,| +----------+ +----------+
| 12345 | |2001:db8::231)| | 12345 |
+----------+ +--------------+ +----------+
| IP4(A,B) | | UDP | | IP4(A,B) |
+----------+ +--------------+ +----------+
| 16002 |
+--------------+
| 12345 |
+--------------+
| IP4(A,B) |
+--------------+
Figure 2: Packet processing in IPv6 network with SR-MPLS islands
o PE1 receives IPv4 traffic from A and headed to B
o PE1 PUSHes the VPN label 12345 and the prefix-SID 16002 of PE2
o Traffic is steered in MPLS island 1 according to the top label
16002
o Traffic reaches node 121, whose next-hop towards 16002 is not
MPLS-enabled
* Node 121 has determined(*) that traffic to 16002 should be sent
over an IP/UDP tunnel to node 231
* Node 121 encapsulates the traffic with IPv6 and UDP header to
2001:db8::231
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o Node 231 removes the IP/UDP encapsulation, exposes the MPLS label
16002 and forwards the traffic accordingly
o Traffic is steered in MPLS island 2 according to the top label
16002
o (PHP: Penultimate node POPs label 16002 and sends the traffic to
PE2)
o PE2 looks up the exposed VPN label 12345 and forwards the traffic
accordingly.
(*) Node 121 determines that node 231 is the closest MPLS- and IP/
UDP-pop-capable node on the shortest path to PE2 using a technique
outside the scope of the document.
5. IANA Considerations
None
6. Acknowledgements
TBD
7. Informative References
[I-D.ietf-idr-bgp-ls-segment-routing-ext]
Previdi, S., Talaulikar, K., Filsfils, C., Gredler, H.,
and M. Chen, "BGP Link-State extensions for Segment
Routing", draft-ietf-idr-bgp-ls-segment-routing-ext-16
(work in progress), June 2019.
[I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Sivabalan, S., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", draft-
ietf-spring-segment-routing-policy-07 (work in progress),
May 2020.
[I-D.ietf-spring-sr-service-programming]
Clad, F., Xu, X., Filsfils, C., daniel.bernier@bell.ca,
d., Li, C., Decraene, B., Ma, S., Yadlapalli, C.,
Henderickx, W., and S. Salsano, "Service Programming with
Segment Routing", draft-ietf-spring-sr-service-
programming-02 (work in progress), March 2020.
[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>.
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[RFC8287] Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya,
N., Kini, S., and M. Chen, "Label Switched Path (LSP)
Ping/Traceroute for Segment Routing (SR) IGP-Prefix and
IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data
Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017,
<https://www.rfc-editor.org/info/rfc8287>.
[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>.
[RFC8663] Xu, X., Bryant, S., Farrel, A., Hassan, S., Henderickx,
W., and Z. Li, "MPLS Segment Routing over IP", RFC 8663,
DOI 10.17487/RFC8663, December 2019,
<https://www.rfc-editor.org/info/rfc8663>.
[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>.
Authors' Addresses
Clarence Filsfils (editor)
Cisco Systems
Email: cfilsfil@cisco.com
Francois Clad (editor)
Cisco Systems
Email: fclad@cisco.com
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Ketan Talaulikar
Cisco Systems
Email: ketant@cisco.com
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