Juniper ACX2000 Configuration Guide

Example: Configuring Remote LFA over LDP Tunnels in OSPF Networks
In an OSPF network, a loop free alternate(LFA) is a directly connected neighbor that
provides precomputed backup paths to the destinations reachable through the protected
link on the point of local repair (PLR). A remote LFA is not directly connected to the PLR
and provides precomputed backup paths using dynamically created LDP tunnels to the
remote LFA node. The PLR uses this remote LFA backup path when the primary link fails.
The primary goal of the remote LFA is to increase backup coverage for the OSPF networks
and provide protection for Layer 1 metro-rings. This example shows how to configure
remote LFA for LDP tunnels in an OSPF network for extending backup protection.
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Requirements on page 550
•
Overview on page 550
•
Configuration on page 551
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Verification on page 558
Requirements
This example uses the following hardware and software components:
•
One ACX5000 router and eight other routers with OSPF protocol and LDP enabled on
the connected interfaces.
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Junos OS Release 15.1X54–D60 running on ACX5000 routers.
•
Junos OS Release 14.2 or later running on other supporting devices.
Before you configure remote LFA over LDP tunnels in an OSPF networks, make sure of
the following:
•
LDP is enabled on the loopback interface. Without a loopback interface, LDP targeted
adjacency cannot be formed. Remote LFA cannot be configured without LDP targeted
adjacency.
•
Remote LFA must allow asymmetric remote neighbor discovery—that is, it must send
periodic targeted hello messages to the router that initiated the remote neighbor for
LDP auto targeted adjacency.
•
Link protection or node-link protection must be configured on the point of local repair
(PLR).
Overview
The example includes one ACX5000 router and eight other routers in a ring topology.
Configure the OSPF protocol on the directly connected interfaces. Device R0 is the
ACX5000 router and Device R6 is the PLR. This example verifies that Junos OS updates
the routing table of Device R6 with LDP next-hop routes as the backup route.
Topology
In the topology Figure 28 on page 551 shows the remote LFA over LDP tunnels in OSPF
networks is configured on Device R6.
Copyright © 2017, Juniper Networks, Inc.550
ACX Series Universal Access Router Configuration Guide

Juniper ACX2000 Specifications

General

Brand	Juniper
Model	ACX2000
Category	Network Router
Language	English