Switch Fabric and Routing Engine (SRE) Module in an EX8208 Switch

The Switch Fabric and Routing Engine (SRE) module performs switching and system management functions in an EX8208 switch. See Figure 1.

You can install one or two SRE modules in an EX8208 switch. A base configuration EX8208 switch has only one SRE module. See EX8208 Switch Configurations. You can add a second SRE module to the configuration for Routing Engine and switch control redundancy. See Understanding EX8208 Switch Component and Functionality Redundancy.

The SRE modules install horizontally into the front of the chassis in slots labeled SRE0 and SRE1.

Figure 1: 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.

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.
• 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.

• USB port—Provides an interface through which you can install the Junos OS manually. See USB Port Specifications for an EX Series Switch.
• Auxiliary port—This port is not enabled on the EX8200 switch. It is reserved for future use.
• Console port—Connects the SRE module to a system console through a cable with an RJ-45 connector. See Connecting an EX Series Switch to a Management Console.
• Management port—Connects the SRE module through an Ethernet connection to a management LAN (or any other device that plugs into an Ethernet connection) for out-of-band management. See Connecting an EX Series Switch to a Network for Out-of-Band Management.
• Ejector levers—Used for installing and removing the SRE module.
• Captive screws—Secure the SRE module in place.