}
}
}
Related
Documentation
MXSeries Ethernet Services Routers SolutionsPage
EthernetRing Protection on page 145
Example:ViewingEthernet Ring Protection Status—NormalRing Operation on page 171
Example:Viewing Ethernet Ring ProtectionStatus—Ring Failure Conditionon page 172
Example:Configuring Load Balancing Within Ethernet Ring Protection forMX SeriesRouters
MXSeries routers support Ethernet ring protection (ERP) to help achievehigh reliability
andnetwork stability. ERP is used in router or bridgenetworks to protect against link
failure.A single-ring topology is configuredthat uses one specific link called a ring
protectionlink (RPL) to protect the whole ring. When all linksare up and running, the
RPLblocks trafficand remains idle. However,if a link fails, the RPL routes trafficto bypass
thefailure on the ring.
MXSeries routers now support ERP ring instances. Whereastraffic in a ring topology
followsthe same path, traffic within a ring instanceuses data channels to allow some
trafficto pass through one path whileother traffic can follow a different one. Dividing
trafficin this way supports traffic load-balancingin the ring.
Thisexample describes how to use ERP with ring instancesto load-balance traffic while
stillproviding network protection from link failure:
Requirementson page 154
Overviewand Topologyon page 154
Configurationon page 157
Verificationon page 166

Requirements

Thisexample uses the following hardwareand software components:
TwoMX Series routersacting as core switches
OneMX Series router acting as an aggregationswitch
JunosOS Release 10.2 or laterfor MX Series routers

Overviewand Topology

Figure24 on page155 displays the topology for this example.The topology containsthree
MXSeries routers. CS1 and CS2 act as corerouters in the topology, and AS1 actsas an
aggregationswitch. Each router hastwo ring instances, ring-1 and ring-2. All nodes on
thering coordinate protection activities byexchanging messages through the Ethernet
ringautomatic protectionswitching (R-APS) messaging protocol. Eachring instance has
Copyright© 2010, Juniper Networks,Inc.154
Junos10.4 MX Series Ethernet ServicesRouters Solutions Guide