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EX8208 Host Subsystem

 

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
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 in an EX8208 Switch

Each Switch Fabric and Routing Engine (SRE) module has four LEDs on the left side of the module’s front panel. See Figure 2. Table 1 describes these LEDs, their colors and states, and the status they indicate.

Figure 2: SRE Module LEDs in an EX8208 Switch
SRE Module LEDs in an EX8208 Switch

Table 1: SRE Module LEDs of an EX8208 Switch

LED Label (Description)

Color

State and Description

ON (Power On)

Green

SRE module is powered on.

Unlit

SRE module is powered off.

ST (Status)

Green

  • On steadily—SRE module is operating normally.

  • Blinking—SRE module is booting.

Yellow

  • On steadily—SRE module has failed.

Unlit

SRE module is offline.

MS (Master)

Green

  • On steadily—SRE module is the master.

  • Blinking—SRE module is in standby mode.

    Note: For EX8208 switches, running a Junos OS release prior to Release 10.2R1, the MS led on the backup SRE module remains unlit. To resolve this issue, upgrade the switch to Junos OS Release 10.2R1 or higher.

Unlit

SRE module is powered off.

SF (Switch Fabric)

Green

  • On steadily—Switch fabric in the SRE module is operating normally.

  • Blinking—Switch fabric in the SRE module is in standby mode.

Yellow

Switch fabric in the SRE module has failed.

Unlit

SRE module is powered off.

Switch Fabric (SF) Module in an EX8208 Switch

The Switch Fabric (SF) module provides switching functionality. See Figure 3.

An EX8208 switch can have either zero SF modules or one SF module. The base configuration of an EX8208 switch includes one SF module. See EX8208 Switch Configurations.

Figure 3: SF Module in an EX8208 Switch
SF Module in an EX8208 Switch

The SF module can be installed only in the slot labeled SF. The SF module is keyed so that it does not fit in the other slots in the chassis. See Slot Numbering for an EX8208 Switch.

In the base configuration, an SF module is used with a single Switch Fabric and Routing Engine (SRE) module to build a nonredundant system that provides full bandwidth. However, a base configuration EX8208 switch has no Routing Engine and switch control redundancy or switch fabric redundancy. In a base configuration, the main function of the SF module is to switch data between line cards. See Understanding EX8208 Switch Component and Functionality Redundancy.

In a redundant configuration, an SF module is used with two SRE modules to achieve full bandwidth along with Routing Engine and switch control redundancy and switch fabric redundancy. In a redundant configuration, the main function of the SF module is to provide a redundant switching plane for the switch. See Understanding EX8208 Switch Component and Functionality Redundancy.

In a redundant configuration, the SF module is hot-pluggable. However, in the base configuration, you must take the SF module offline before removing it.

The SF module contains logic that determines which SRE module is the master. The master SRE module controls many internal functions of the SF module.

The SF module provides these functions:

  • Provide redundant data path connectivity for the switch in the redundant configuration

  • Provide nonredundant data path connectivity for the switch in the base configuration

The SF module has these components:

  • SF module LEDs—Indicate system status. See SF Module LEDs in an EX8208 Switch.

  • Ejector levers—Used for installing and removing the SF module.

  • Captive screws—Secure the SF module in place.

SF Module LEDs in an EX8208 Switch

The Switch Fabric (SF) module has two LEDs on the left side of the module’s front panel. See Figure 4.Table 2 describes these LEDs, their colors and states, and the status they indicate.

Figure 4: SF Module LEDs in an EX8208 Switch
SF Module LEDs in an EX8208 Switch

Table 2: SF Module LEDs of an EX8208 Switch

LED (Description)

Color

State and Description

ST (Status)

Green

  • On steadily—SF module is operating normally.

  • Blinking—Waiting to be configured by the master Switch Fabric and Routing Engine (SRE) module.

Yellow

SF module has failed.

Unlit

SF module is offline.

SF (Switch Fabric)

Green

On steadily—Switch fabric in SF module is operating normally.

Blinking—Switch fabric in SF module is offline.

Yellow

On steadily—Switch fabric in SF module has failed.

Unlit

SF module is powered off.