LDP Extensions to Support Maximally Redundant Trees
RFC 8320
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Type |
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RFC - Proposed Standard
(February 2018; No errata)
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Last updated |
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2018-02-22
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Replaces |
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draft-atlas-mpls-ldp-mrt
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Stream |
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IETF
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Formats |
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plain text
pdf
html
bibtex
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Reviews |
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WG state
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Submitted to IESG for Publication
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Document shepherd |
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Loa Andersson
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Shepherd write-up |
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Show
(last changed 2017-03-03)
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| IESG |
IESG state |
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RFC 8320 (Proposed Standard)
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Consensus Boilerplate |
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Yes
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Telechat date |
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Responsible AD |
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Deborah Brungard
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Send notices to |
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tsaad@cisco.com, mpls-chairs@ietf.org
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| IANA |
IANA review state |
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Version Changed - Review Needed
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IANA action state |
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RFC-Ed-Ack
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Internet Engineering Task Force (IETF) A. Atlas
Request for Comments: 8320 K. Tiruveedhula
Category: Standards Track C. Bowers
ISSN: 2070-1721 Juniper Networks
J. Tantsura
Individual
IJ. Wijnands
Cisco Systems, Inc.
February 2018
LDP Extensions to Support Maximally Redundant Trees
Abstract
This document specifies extensions to the Label Distribution Protocol
(LDP) to support the creation of Label Switched Paths (LSPs) for
Maximally Redundant Trees (MRTs). A prime use of MRTs is for unicast
and multicast IP/LDP Fast Reroute, which we will refer to as
"MRT-FRR".
The sole protocol extension to LDP is simply the ability to advertise
an MRT Capability. This document describes that extension and the
associated behavior expected for Label Switching Routers (LSRs) and
Label Edge Routers (LERs) advertising the MRT Capability.
MRT-FRR uses LDP multi-topology extensions, so three multi-topology
IDs have been allocated from the MPLS MT-ID space.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8320.
Atlas, et al. Standards Track [Page 1]
RFC 8320 LDP Extensions to Support MRTs February 2018
Copyright Notice
Copyright (c) 2018 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
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Atlas, et al. Standards Track [Page 2]
RFC 8320 LDP Extensions to Support MRTs February 2018
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Overview of LDP Signaling Extensions for MRT . . . . . . . . 6
4.1. MRT Capability Advertisement . . . . . . . . . . . . . . 6
4.1.1. Interaction of MRT Capability and MT Capability . . . 7
4.1.2. Interaction of LDP MRT Capability with IPv4 and IPv6 8
4.2. Use of the Rainbow MRT MT-ID . . . . . . . . . . . . . . 8
4.3. MRT-Blue and MRT-Red FECs . . . . . . . . . . . . . . . . 8
4.4. Interaction of MRT-Related LDP Advertisements with the
MRT Topology and Computations . . . . . . . . . . . . . . 9
5. LDP MRT FEC Advertisements . . . . . . . . . . . . . . . . . 10
5.1. MRT-Specific Behavior . . . . . . . . . . . . . . . . . . 10
5.1.1. ABR Behavior and Use of the Rainbow FEC . . . . . . . 10
5.1.2. Proxy-Node Attachment Router Behavior . . . . . . . . 11
5.2. LDP Protocol Procedures in the Context of MRT Label
Distribution . . . . . . . . . . . . . . . . . . . . . . 12
5.2.1. LDP Peer in RFC 5036 . . . . . . . . . . . . . . . . 12
5.2.2. Next Hop in RFC 5036 . . . . . . . . . . . . . . . . 13
5.2.3. Egress LSR in RFC 5036 . . . . . . . . . . . . . . . 13
5.2.4. Use of Rainbow FEC to Satisfy Label Mapping Existence
Requirements in RFC 5036 . . . . . . . . . . . . . . 15
5.2.5. Validating FECs in the Routing Table . . . . . . . . 15
5.2.6. Recognizing New FECs . . . . . . . . . . . . . . . . 15
5.2.7. Not Propagating Rainbow FEC Label Mappings . . . . . 15
6. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. Potential Restrictions on MRT-Related MT-ID Values Imposed by
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