RFC 5443 · INFORMATIONAL · 2009

LDP IGP Synchronization

Overview

RFC 5443, “LDP IGP Synchronization”, is an Informational document published in March 2009 by M. Jork, A. Atlas, L. Fang. It has since been updated by RFC 6138. The canonical text is published by the RFC Editor.

Abstract

In certain networks, there is dependency on the edge-to-edge Label Switched Paths (LSPs) setup by the Label Distribution Protocol (LDP), e.g., networks that are used for Multiprotocol Label Switching (MPLS) Virtual Private Network (VPN) applications. For such applications, it is not possible to rely on Internet Protocol (IP) forwarding if the MPLS LSP is not operating appropriately. Blackholing of labeled traffic can occur in situations where the Interior Gateway Protocol (IGP) is operational on a link on which LDP is not. While the link could still be used for IP forwarding, it is not useful for MPLS forwarding, for example, MPLS VPN applications or Border Gateway Protocol (BGP) route-free cores. This document describes a mechanism to avoid traffic loss due to this condition without introducing any protocol changes. This memo provides information for the Internet community.

Abstract as published in the RFC, via rfc-editor.org.

What “Informational” means

Published for the general information of the community. It does not define an IETF standard and carries no standards-track status.

Read this RFC

The canonical text of RFC 5443 is hosted at rfc-editor.org. Available in TXT,HTML.

Relationships to other RFCs
Updated by
RFC 6138
Other RFCs from 2009

Who Is Online

In total there are 107 users online: 0 registered, 97 guests and 10 bots.

Most users ever online was 5,555 on 17 Jul 2026, 3:23 am.

Bots: AhrefsBot Applebot Baiduspider Bingbot Googlebot Majestic Other Bot Other Crawler PetalBot SemrushBot

Users active in the past 15 minutes. Total registered members: 372