Segment Routing interworking with LDP
draft-ietf-spring-segment-routing-ldp-interop-08
Network Working Group C. Filsfils, Ed.
Internet-Draft S. Previdi, Ed.
Intended status: Standards Track A. Bashandy
Expires: December 17, 2017 Cisco Systems, Inc.
B. Decraene
S. Litkowski
Orange
June 15, 2017
Segment Routing interworking with LDP
draft-ietf-spring-segment-routing-ldp-interop-08
Abstract
A Segment Routing (SR) node steers a packet through a controlled set
of instructions, called segments, by prepending the packet with an SR
header. A segment can represent any instruction, topological or
service-based. SR allows to enforce a flow through any topological
path and service chain while maintaining per-flow state only at the
ingress node to the SR domain.
The Segment Routing architecture can be directly applied to the MPLS
data plane with no change in the forwarding plane. This drafts
describes how Segment Routing operates in a network where LDP is
deployed and in the case where SR-capable and non-SR-capable nodes
coexist.
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 RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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Task Force (IETF). Note that other groups may also distribute
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time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
Filsfils, et al. Expires December 17, 2017 [Page 1]
Internet-Draft Segment Routing and LDP June 2017
This Internet-Draft will expire on December 17, 2017.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. SR/LDP Ship-in-the-night coexistence . . . . . . . . . . . . 3
2.1. MPLS2MPLS co-existence . . . . . . . . . . . . . . . . . 5
2.2. IP2MPLS co-existence . . . . . . . . . . . . . . . . . . 6
3. Migration from LDP to SR . . . . . . . . . . . . . . . . . . 6
4. SR and LDP Interworking . . . . . . . . . . . . . . . . . . . 7
4.1. LDP to SR . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1.1. LDP to SR Behavior . . . . . . . . . . . . . . . . . 8
4.2. SR to LDP . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2.1. SR to LDP Behavior . . . . . . . . . . . . . . . . . 10
5. SR/LDP Interworking Use Cases . . . . . . . . . . . . . . . . 11
5.1. SR Protection of LDP-based Traffic . . . . . . . . . . . 11
5.2. Eliminating Targeted LDP Session . . . . . . . . . . . . 13
5.3. Guaranteed FRR coverage . . . . . . . . . . . . . . . . . 14
5.4. Inter-AS Option C, Carrier's Carrier . . . . . . . . . . 15
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
7. Manageability Considerations . . . . . . . . . . . . . . . . 16
7.1. SR and LDP co-existence . . . . . . . . . . . . . . . . . 16
7.2. SRMS Management . . . . . . . . . . . . . . . . . . . . . 16
7.3. Dataplane Verification . . . . . . . . . . . . . . . . . 17
8. Security Considerations . . . . . . . . . . . . . . . . . . . 17
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