Ethernet Link Redundancy Overview; Ethernet Link Redundancy Configuration Models - Juniper JUNOSE SOFTWARE 11.2.X - LINK LAYER CONFIGURATION GUIDE 7-7-2010 Configuration Manual

JunosE 11.2.x Link Layer Configuration Guide

Ethernet Link Redundancy Overview

Ethernet Link Redundancy Configuration Models

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The following commands add the Ethernet physical interfaces to a LAG bundle named
kanata.
host1(config)#virtual router kanata
host1:kanata(config)#interface lag kanata
host1:kanata(config-if)#member-interface fastEthernet 5/0
host1:kanata(config-if)#member-interface fastEthernet 5/1
The following commands configure a VLAN subinterface for the LAG bundle named
kanata. In the LAG interface identification command (interface lag kanata.1), the number
1 represents the subinterface number for the VLAN subinterface.
host1:kanata(config-if)#encapsulation vlan
host1:kanata(config)#interface lag kanata.1
host1:kanata(config-if)#vlan id 100
The following command creates an MPLS interface.
host1:kanata(config)#mpls
You can use 802.3ad Link Aggregation (LAG) to configure Ethernet link redundancy for
Fast Ethernet and Gigabit Ethernet interfaces. Ethernet link redundancy enables you to
protect against physical link failure and account for network topology changes that
redirect network traffic to redundant ports.
The following configurations are available:
LAG to LAG—Provides redundancy capabilities for two or more ports that are assigned
to a LAG. One member link is configured as the backup interface for all other ports in
the LAG bundle (1:N). Traffic is not forwarded over the backup member interface; it is
disabled until it takes over for an active member interface.
LAG to non-LAG—Provides redundancy capabilities when redundant ports are
connected to a bridged network that has Rapid Spanning Tree Protocol (RSTP)
controlling the topology. This configuration supports only two links in the LAG.
For information about the modules that support link aggregation, see ERX Module Guide,
Appendix A, Module Protocol Support and E120 and E320 Module Guide, Appendix A, IOA
Protocol Support.
The link connections determine the configuration model for link redundancy. The following
connection types are available:
Single-homed—Connections are between the local Ethernet interface and a single
remote device. When the peer is also configured with LAG, LACP can be used to control
link access.
Dual-homed—Connections are between two separate, uncoordinated remote devices.
The remote interfaces can be on the same module or on separate hardware. If LAG is
not configured on the peers, LACP cannot be used to select ports; other protocols such
as RSTP can be used.
Copyright © 2010, Juniper Networks, Inc.