Understanding MPLS and Path Protection on EX Series Switches
Junos MPLS for Juniper Networks EX Series Ethernet Switches provides path protection
to protect your MPLS network from label switched path (LSP) failures.
By default, an LSP routes itself hop-by-hop from the ingress provider edge switch through
the provider switches toward the egress provider edge switch. The LSP generally follows
the shortest path as dictated by the local routing table, usually taking the same path as
destination-based, best-effort traffic. These paths are “soft” in nature because they
automatically reroute themselves whenever a change occurs in a routing table or in the
status of a node or link.
Typically, when an LSP fails, the switch immediately upstream from the failure signals
the outage to the ingress provider edge switch. The ingress provider edge switch calculates
a new path to the egress provider edge switch, establishes the new LSP, and then directs
traffic from the failed path to the new path. This rerouting process can be time-consuming
and prone to failure. For example, the outage signals to the ingress switch might get lost
or the new path might take too long to come up, resulting in significant packet drops.
You can configure path protection by configuring primary and secondary paths on the
ingress switch. If the primary path fails, the ingress switch immediately reroutes traffic
from the failed path to the standby path, eliminating the need for the ingress switch to
calculate a new route and signal a new path. For information about configuring standby
LSPs, see “Configuring Path Protection in an MPLS Network (CLI Procedure)” on page 3391.
Related
Documentation
JUNOS MPLS for EX Series Switches Overview on page 3351
•
•
Understanding JUNOS MPLS Components for EX Series Switches on page 3353
•
Example: Configuring MPLS on EX Series Switches on page 3365
•
Configuring MPLS on Provider Edge Switches (CLI Procedure)
•
Junos OS MPLS Applications Configuration Guide
at
http://www.juniper.net/techpubs/software/junos/junos95/index.html
3357
Copyright © 2010, Juniper Networks, Inc.
Chapter 121: MPLS—Overview
Summary of Contents for JUNOS OS 10.3 - SOFTWARE
Page 325: ...CHAPTER 17 Operational Mode Commands for System Setup 229 Copyright 2010 Juniper Networks Inc ...
Page 1323: ...CHAPTER 56 Operational Mode Commands for Interfaces 1227 Copyright 2010 Juniper Networks Inc ...
Page 2841: ...CHAPTER 86 Operational Commands for 802 1X 2745 Copyright 2010 Juniper Networks Inc ...
Page 3367: ...CHAPTER 113 Operational Mode Commands for CoS 3271 Copyright 2010 Juniper Networks Inc ...
Page 3435: ...CHAPTER 120 Operational Mode Commands for PoE 3339 Copyright 2010 Juniper Networks Inc ...
Page 3529: ...CHAPTER 126 Operational Mode Commands for MPLS 3433 Copyright 2010 Juniper Networks Inc ...