Specifications

Copyright © 2009, Juniper Networks, Inc. 21
DESIGN GUIDE - Data Center LAN Connectivity Design Guide
Each EX4200 line of switch supports optional front-panel uplink modules supporting either four GbE or two 10
GbE ports for high-speed connections to aggregation or core switches. These uplinks support online insertion
and removal.
Figure 10: Virtual chassis technology
Pay-As-You-Grow Scalability2.
The Juniper Networks Virtual Chassis technology enables a data center to add as many EX4200 line of
switches as needed to meet its connectivity needs while delivering true chassis-like functionality. Juniper
Networks’ unique pay-as-you-grow model allows a single 1 RU top-of-rack EX4200 switch to be deployed and
incrementally add up to nine more switches for a total of 10 switches. Resiliently interconnected via a 128
Gbps virtual backplane or 10 GbE uplink module, a fully-loaded Virtual Chassis configuration supports up to
240 100BASE-FX/1000BASE-X ports, 480 10/100/1000BASE-T ports, or any combination of the two, plus up to
20 10 GbE uplink ports. Not only does Virtual Chassis technology lower capital expenses when compared to
legacy chassis systems by requiring less upfront investments, but it dramatically reduces operating expenses
by enabling any group of interconnected switches to appear and be managed as a single switch. Coupled with
the incremental, pay-as-you-grow model, the compact form factor of the EX4200 switches enables the data
center to save not only on upfront and recurring rack space usage but also on costly power and cooling fees.
Additionally, with the virtual-chassis configuration, cabling is greatly simplified.
Carrier-class Reliability3.
The EX4200 Ethernet Switches with Virtual Chassis technology provide the same HA features as modular
chassis-based systems. Each switch supports internal redundant, load-sharing, hot-swappable AC or DC power
supplies, as well as a field-replaceable hot-swappable fan tray with redundant blowers, any of which can fail
without affecting operations.
Virtual Chassis technology provides unparalleled device and link HA utilizing the virtual backplane protocol
and JUNOS Software. Each set of interconnected switches with Virtual Chassis technology automatically
takes full advantage of the multiple route engines present to deliver graceful protocol restart. Graceful Route
Engine Switchover (GRES) and non-stop forwarding ensure uninterrupted operation in the rare event of any
individual switch failure. For added device and link HA, the EX4200 switches can be configured to address any
requirements. For example, a single virtual-chassis configuration of 10 switches could instead be configured as
two five-switch virtual-chassis configurations, or in any other desired combination.
Location Independence4.
Another key feature of the Virtual Chassis technology is that the virtual chassis protocol can also be extended
across the 10 GbE uplink ports to interconnect switches that are more than a few meters apart, creating a single
virtual switch that spans multiple wiring closets, floors or even data center server racks. Even when separated
by long distances, interconnected switches with Virtual Chassis technology can be managed, monitored,
upgraded and otherwise treated as a single resilient switch, dramatically reducing recurring management and
maintenance costs. This enables either top-of-rack or end-of-row deployment with the EX4200 switches.
Top-of-Rack Deploymentsa.
EX4200 line
T Series
EX4200 line
EX4200 line
Virtual Chassis
Switch: 1 RU;
24 GbE ports + 2 10GbE
Legacy Aggregation Switch:
12-15 Rack Units (RUs)
48-288 GbE ports + 4 10GbE
Virtual Chassis
Switch: 2 RU;
48 GbE ports + 4 10GbE
Virtual Chassis
Switch: 4 RU;
96 GbE ports + 8 10GbE