Graceful Restart Mechanism for Label Distribution Protocol (RFC3478)
Original Publication Date: 2003-Feb-01
Included in the Prior Art Database: 2003-Feb-19
Internet Society Requests For Comment (RFCs)
M. Leelanivas: AUTHOR [+3]
This document describes a mechanism that helps to minimize the negative effects on MPLS traffic caused by Label Switching Router's (LSR's) control plane restart, specifically by the restart of its Label Distribution Protocol (LDP) component, on LSRs that are capable of preserving the MPLS forwarding component across the restart.
Network Working Group M. Leelanivas
Request for Comments: 3478 Y. Rekhter
Category: Standards Track Juniper Networks
Graceful Restart Mechanism for Label Distribution Protocol
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document describes a mechanism that helps to minimize the
negative effects on MPLS traffic caused by Label Switching Router's
(LSR's) control plane restart, specifically by the restart of its
Label Distribution Protocol (LDP) component, on LSRs that are capable
of preserving the MPLS forwarding component across the restart.
The mechanism described in this document is applicable to all LSRs,
both those with the ability to preserve forwarding state during LDP
restart and those without (although the latter needs to implement
only a subset of the mechanism described in this document).
Supporting (a subset of) the mechanism described here by the LSRs
that can not preserve their MPLS forwarding state across the restart
would not reduce the negative impact on MPLS traffic caused by their
control plane restart, but it would minimize the impact if their
neighbor(s) are capable of preserving the forwarding state across the
restart of their control plane and implement the mechanism described
The mechanism makes minimalistic assumptions on what has to be
preserved across restart - the mechanism assumes that only the actual
MPLS forwarding state has to be preserved; the mechanism does not
require any of the LDP-related states to be preserved across the
Leelanivas, et al. Standards Track [Page 1]
RFC 3478 Graceful Restart Mechanism for LDP February 2003
The procedures described in this document apply to downstream
unsolicited label distribution. Extending these procedures to
downstream on demand label distribution is for further stu...