Switch Fabric (SF) Module in an EX8208 Switch

The Switch Fabric (SF) module provides switching functionality. See Figure 1.

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 1: 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.