EX8216 Host Subsystem
Routing Engine (RE) Module in an EX8216 Switch
The Routing Engine (RE) module performs system control, system management, FRU configuration, and FRU management functions in an EX8216 switch. An RE module contains a Routing Engine. See Figure 1.
You can install one or two RE modules in an EX8216 switch. A base configuration EX8216 switch (AC version) has only one RE module. See EX8216 Switch Configurations. You can add a second RE module to the configuration for Routing Engine and system control redundancy. See Understanding EX8216 Switch Component and Functionality Redundancy.
The RE modules install horizontally into the top front of the chassis in slots labeled RE0 and RE1.

We recommend that you install two RE modules for redundancy. If you install only one RE module, we recommend that you install it in slot RE0. See Slot Numbering for an EX8216 Switch.
If two RE modules are installed, one RE module functions as the master and the other acts as the backup. If the master RE module fails or is removed, the backup module takes over as the master RE module. When the RE modules are configured for graceful switchover, the backup RE module automatically synchronizes its configuration and state with those of the master RE module. Any update to the master RE module is replicated on the backup RE module. If the backup module assumes mastership, packet forwarding continues through the switch.
We recommend, however, that you always take an RE module offline before removing it. If only one RE module is installed, we recommend that you disable the switch by halting the RE module (thus taking it offline) before removing the RE module. See Taking the RE Module Offline in an EX8216 Switch.
The RE module provides these functions:
Powers the line cards on and off
Powers the Switch Fabric (SF) modules on and off
Performs routing functions for the switch
Controls system resets and the boot sequence for the switch
Monitors and controls the speed of the fans in the fan trays
Monitors and controls the LCD panel and chassis status LEDs
Monitors the communication of the line cards with the switch fabric on the Switch Fabric (SF) modules
Monitors the status of the power supplies
The RE module has these components:
RE module LEDs—Indicate system status. See RE Module LEDs in an EX8216 Switch.
Recessed reset button—Power cycles the RE module when pressed.
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 EX8200 switches. It is reserved for future use.
Console port—Connects the RE module to a system console through a cable with an RJ-45 connector. See Connecting a Device to a Management Console by Using an RJ-45 Connector.
Management port—Connects the RE 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 a Device to a Network for Out-of-Band Management.
Ejector levers—Used for installing and removing the RE module.
Captive screws—Secure the RE module in place.
RE Module LEDs in an EX8216 Switch
Each Routing Engine (RE) 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.
Table 1: RE Module LEDs in an EX8216 Switch
LED Label (Description) | Color | State and Description |
---|---|---|
ON (Power On) | Green | RE module is powered on. |
Unlit | RE module is powered off. | |
ST (Status) | Green |
|
Yellow |
| |
Unlit | RE module is offline. | |
MS (Master) | Green |
|
Unlit | RE module is powered off. | |
SF (Switch Fabric) | Green |
|
Yellow | Switch fabric in one or more SF modules has failed. | |
Unlit | RE module is powered off. |
Switch Fabric (SF) Modules in an EX8216 Switch
The Switch Fabric (SF) modules provide switching functionality to an EX8216 switch. See Figure 3.
An EX8216 switch can have up to eight SF modules. We recommend that you install all eight SF modules in an EX8216 switch to support maximum midplane performance for the installed line cards. All shipping configurations of an EX8216 switch include eight SF modules. See EX8216 Switch Configurations.
In the EX8216 switch, all eight SF modules are simultaneously active when the switch is operational. All SF modules are fully connected to all installed line cards. If a single SF module fails, the input/output traffic for that module is load-balanced among the remaining SF modules, providing graceful degradation in midplane performance. The impact of an SF module failure on the performance of an EX8216 switch varies based on the type of line cards installed in the switch and the traffic mix flowing through them. In an EX8216 switch configuration that is fully loaded with 8-port 10-Gigabit Ethernet SFP+ line cards, if one SF module fails, the remaining seven SF modules still have sufficient switching capacity to maintain continuous switch operation at full wire-rate performance.

The SF modules are installed in the rear of the chassis in the slots labeled SF7 through SF0 (from left to right). See Slot Numbering for an EX8216 Switch.
The SF modules are hot-insertable and hot-removable field-replaceable units (FRUs). However, you must take the SF modules offline before removing them. See Taking the SF Module Offline in an EX8216 Switch.
The SF modules contain logic that determines which RE module is the master. The master RE module controls many internal functions of the SF modules.
The SF modules provide these functions:
Provide data path connectivity for the switch (switch data between line cards)
Each SF module has these components:
SF module LEDs—Indicate system status. See SF Module LEDs in an EX8216 Switch.
Ejector levers—Used for installing and removing the SF module.
Handle—Facilitates installing and removing the SF module.
Captive screws—Secure the SF module in place.
SF Module LEDs in an EX8216 Switch
Each Switch Fabric (SF) module has two LEDs on the top of the module’s front panel. See Figure 4.

Table 2 describes these LEDs, their colors and states, and the status they indicate.
Table 2: SF Module LEDs in an EX8216 Switch
LED (Description) | Color | State and Description |
---|---|---|
ST (Status) | Green |
|
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. |