Routing Engine

The Routing Engine is an Intel-based PC platform that runs JUNOS software. Software processes that run on the Routing Engine maintain the routing tables, manage the routing protocols used on the device, control the device interfaces, control some chassis components, and provide the interface for system management and user access to the device.

You can install only one Routing Engine in the device. The Routing Engine installs into the front of the chassis in the vertical slot in the SCB labeled 0 or 1.

A USB port on the Routing Engine accepts a USB memory card that allows you to load JUNOS software.

Figure 1: Routing Engine

Routing Engine Components

The Routing Engine (shown in Figure 1) consists of the following components:

• CPU—Runs JUNOS software to maintain the services gateway's routing tables and routing protocols. It has a Pentium-class processor.
• DRAM—Provides storage for the routing and forwarding tables and for other Routing Engine processes.
• USB port—Provides a removable media interface through which you can install the JUNOS software manually. (See Figure 2.) JUNOS supports USB version 1.0.
• Internal flash disk—Provides primary storage for software images, configuration files, and microcode. The disk is a fixed compact flash and is inaccessible from outside the services gateway.
• Hard disk—Provides secondary storage for log files, memory dumps, and rebooting the system if the internal compact flash disk fails.
• HDD LED—Indicates disk activity for the hard disk drive.
• Management ports—Each Routing Engine has one 10/100-Mbps Ethernet port for connecting to a management network, and two asynchronous serial ports—one for connecting to a console and one for connecting to a modem or other auxiliary device. The interface ports are labelled AUX, CONSOLE, and ETHERNET.
• EEPROM—Stores the serial number of the Routing Engine.
• Reset button—Reboots the Routing Engine when pressed.
• Online/Offline button—Not supported in the current release.
• Extractor clips—Used for inserting and extracting the Routing Engine.
• Captive screws—Secure the Routing Engine in place.

Figure 2: USB Memory Device in a Routing Engine

The Routing Engine has four LEDs that indicate its status. The LEDs, labeled MASTER, HDD, ONLINE, and FAIL, are located directly on the faceplate of the Routing Engine. Table 1 describes the functions of the Routing Engine LEDs.

Table 1: Routing Engine LEDs

Routing Engine Interface Ports and Status Indicators

In the center of the Routing Engine are three ports that connect the Routing Engine to one or more external devices on which system administrators can issue JUNOS command-line interface (CLI) commands to manage the device (see Figure 1).

The ports with the indicated labels function as follows:

• AUX—Connects the Routing Engine to a laptop, modem, or other auxiliary device through a cable with an RJ-45 connector.
• CONSOLE—Connects the Routing Engine to a system console through a cable with an RJ-45 connector.
• ETHERNET—Connects the Routing Engine through an Ethernet connection to a management LAN (or any other device that plugs into an Ethernet connection) for out-of-band management. The port uses an autosensing RJ-45 connector to support10-Mbps or 100-Mbps connections. Two small LEDs on the top of the port indicate the connection in use: the LED flashes yellow or green for a 10-Mbps or 100-Mbps connection, and the LED is light green when traffic is passing through the port.

For information about the pinouts for the connectors, see the SRX 5600 Services Gateway Hardware Guide or the SRX 5800 Services Gateway Hardware Guide.

Routing Engine Boot Sequence

The Routing Engine boots from the storage media in this order: the USB device (if present), then the internal flash disk, then the hard disk, then the LAN.

If the Routing Engines are configured for graceful switchover, the backup Routing Engine automatically synchronizes its configuration and state with the master Routing Engine. Any update to the master Routing Engine state is replicated on the backup Routing Engine. If the backup Routing Engine assumes mastership, packet forwarding continues through the services gateway without interruption. For more information about graceful switchover, see the JUNOS System Basics Configuration Guide.

Note: For specific information about Routing Engine components (for example, the amount of DRAM), issue the show chassis routing-engine command.