PathErr Message Triggered MPLS and GMPLS LSP Reroutes
RFC 5710
Internet Engineering Task Force (IETF) L. Berger
Request for Comments: 5710 LabN
Category: Standards Track D. Papadimitriou
ISSN: 2070-1721 Alcatel Lucent
JP. Vasseur
Cisco
January 2010
PathErr Message Triggered MPLS and GMPLS LSP Reroutes
Abstract
This document describes how Resource ReserVation Protocol (RSVP)
PathErr messages may be used to trigger rerouting of Multi-Protocol
Label Switching (MPLS) and Generalized MPLS (GMPLS) point-to-point
Traffic Engineering (TE) Label Switched Paths (LSPs) without first
removing LSP state or resources. Such LSP rerouting may be desirable
in a number of cases, including, for example, soft-preemption and
graceful shutdown. This document describes the usage of existing
Standards Track mechanisms to support LSP rerouting. In this case,
it relies on mechanisms already defined as part of RSVP-TE and simply
describes a sequence of actions to be executed. While existing
protocol definitions can be used to support reroute applications,
this document also defines a new reroute-specific error code to allow
for the future definition of reroute-application-specific error
values.
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 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5710.
Berger, et al. Standards Track [Page 1]
RFC 5710 MPLS and GMPLS LSP Reroutes January 2010
Copyright Notice
Copyright (c) 2010 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................3
1.1. Conventions Used in This Document ..........................4
2. Reroute Requests ................................................4
2.1. Processing at Requesting Node ..............................4
2.1.1. Reroute Request Timeouts ............................5
2.2. Processing at Upstream Node ................................6
2.3. Processing at Ingress ......................................6
3. Example Reroute Requests ........................................7
3.1. Node Reroute Request .......................................7
3.2. Interface Reroute Request ..................................7
3.3. Component Reroute Request ..................................8
3.4. Label Reroute Request ......................................9
4. IANA Considerations .............................................9
5. Security Considerations ........................................10
6. References .....................................................10
6.1. Normative References ......................................10
6.2. Informative References ....................................11
7. Acknowledgments ................................................11
Berger, et al. Standards Track [Page 2]
RFC 5710 MPLS and GMPLS LSP Reroutes January 2010
1. Introduction
The Resource ReserVation Protocol (RSVP), see [RFC2205], has been
extended to support the control of Traffic Engineering (TE) Label
Switched Paths (LSPs) for both Multi-Protocol Label Switching (MPLS)
and Generalized MPLS (GMPLS) in, respectively, [RFC3209] and
[RFC3473]. In all cases, a PathErr message is used to report errors
to nodes upstream of the error-detecting node. As defined in
[RFC2205] and left unmodified by [RFC3209], PathErr messages "do not
change path state in the nodes through which they pass".
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