Juniper EX6210 Complete Hardware Manual page 31

Copyright © 2014, Juniper Networks, Inc.
SRE modules—An EX6210 switch can have either one or two Switch Fabric and Routing
Engine (SRE) modules. At least one SRE module must be installed in the switch. If two
SRE modules are installed, one SRE module functions as the master and the other
functions as the backup. If the master SRE module fails or is removed the backup
module takes over as the master SRE module.
When the SRE modules are configured for graceful switchover, the backup SRE module
automatically synchronizes its configuration and state with those of the master SRE
module. Any update to the master SRE module is replicated on the backup SRE module.
If the backup module assumes mastership, packet forwarding continues through the
switch.
Each SRE module provides 64 Gbps of full-duplex bandwidth per line card slot. If only
one SRE module is installed in a chassis, it supports 384 ports on eight line cards with
3:2 oversubscription. If two SRE modules are installed in a chassis, they provide 128
Gbps of full-duplex bandwidth to each line card slot, allowing all 384 ports to operate
at wire speed.
Power supplies—You can install up to four AC or four DC power supplies in an EX6210
switch. Each power supply connects to the backplane of the chassis, which distributes
the output power produced by the power supplies to different switch components.
(See "Backplane in an EX6210 Switch" on page
to all the components in the switch.
An N+1 power configuration is recommended for EX6200 switches. By default, the
power management feature in EX6200 switches is configured to manage the power
supplies for N+1 redundancy, in which one power supply is held in reserve for backup
if any one of the other power supplies is removed or fails. In an N+1 power configuration,
if one power supply fails or is removed, the remaining power supplies continue to supply
power for the entire system without interruption.
If dual power feed redundancy is required, you can configure power management to
manage the power supplies for N+N redundancy. In N+N redundancy, power
management allocates half of the online power supplies to normal operating power
and half to redundant power. If you have an odd number of online power supplies,
power management allocates one more power supply to normal operating power than
to redundant power. To configure the power supply redundancy of your switch, see
Configuring Power Supply Redundancy (CLI Procedure).
For details about the power supply, see
page 38 and "DC Power Supply in an EX6200 Switch" on page
CAUTION: Mixing different types (AC and DC or AC power supplies of
different wattage) of power supplies in the same chassis is not supported.
Mixing low-voltage input line and high-voltage input line power feeds in
the same chassis is not supported.
Cooling system—The cooling system in an EX6210 switch consists of a single fan tray.
The fan tray contains six fans, three rows of two fan each. Under normal operating
conditions, the fans in the fan tray run at less than full speed.
Chapter 1: EX6210 Switch Overview
56.) Each power supply provides power
"AC Power Supplies in an EX6200 Switch" on
49.
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