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    RE-S-2000 Routing Engine Description

    RE-S-2000 Routing Engine Components

    Figure 1 shows the Routing Engine 2000.

    Figure 1: Routing Engine 2000

    Routing Engine 2000

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

    • CPU—Runs Junos OS to maintain the router's routing tables and routing protocols..
    • 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 OS manually. Junos OS supports USB version 1.0.
    • CompactFlash card—Provides primary storage for software images, configuration files, and microcode. The CompactFlash card is fixed and is inaccessible from outside the router.
    • Hard drive—Provides secondary storage for log files, memory dumps, and rebooting the system if the CompactFlash card fails.
    • Interface ports—The AUX, CONSOLE, and ETHERNET provide access to management devices. 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.
    • EEPROM—Stores the serial number of the Routing Engine.
    • Reset button—Reboots the Routing Engine when pressed.
    • Online/Offline button—Takes the Routing Engine online or offline when pressed.
    • Extractor clips—Used for inserting and extracting the Routing Engine.
    • Captive screws—Secure the Routing Engine in place.

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

    Routing Engine Boot Sequence

    The router is shipped with the Junos OS preinstalled on the Routing Engine. There are three copies of software:

    • One copy on the CompactFlash card in the Routing Engine.
    • One copy on the hard disk in the Routing Engine.
    • One copy on a USB flash drive that can be inserted into the slot on the Routing Engine faceplate.

    The Routing Engine boots from the storage media in this order: the USB device (if present), then the CompactFlash card, then the hard disk, then the LAN. Normally, the router boots from the copy of the software on the CompactFlash card.

    Published: 2014-03-25