Juniper Networks EX8208 - Manual (Page 51)

Figure 7: SRE Module in an EX8208 Switch
NOTE: We recommend that you install two SRE modules for redundancy. If you install
only one SRE module, we recommend that you install it in slot SRE0. See “Slot
Numbering for an EX8208 Switch” on page 13.
If two SRE modules are installed, one functions as the master and the other acts as the
backup. If the master SRE module fails or is removed, the backup takes over as the master.
If two SRE modules are installed, the backup SRE module is hot-insertable and
hot-removable, but the master SRE module is hot-pluggable. If only one SRE module is
installed, you must halt the SRE module before removing it.
The SRE module provides these functions:
• Provides full fabric connectivity to all line cards installed in the chassis
• Through the switching plane, provides switching functionality to the switch
• Powers the line cards on and off
• Controls system resets and boot sequence for the switch
• Monitors and controls the fan speed, power status for various chassis components,
LCD panel and chassis status LEDs
The SRE module has these components:
• SRE module LEDs—Indicate system status. See “SRE Module LEDs in an EX8208
Switch” on page 26.
• Recessed reset button—Power cycles the SRE module when pressed.
Take the SRE module offline using the CLI before pressing the reset button. See “Taking
the SRE Module Offline in an EX8208 Switch” on page 213.
• USB port—Provides an interface through which you can install the Junos OS manually.
See “USB Port Specifications for an EX Series Switch” on page 57.
• Auxiliary port—This port is not enabled on the EX8200 switch. It is reserved for future
use.
25 Copyright © 2010, Juniper Networks, Inc.
Chapter 2: Component Descriptions