Routing Engine Interface Ports; Routing Engine Boot Sequence - Juniper MX480 Hardware Manual

MX480 Universal Routing Platform Hardware Guide
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Routing Engine Interface Ports

Three ports, located on the right side of the Routing Engine, connect the Routing Engine
to one or more external devices on which system administrators can issue Junos OS
command-line interface (CLI) commands to manage the router.
The ports with the indicated labels function as follows:
AUX —Connects the Routing Engine to a laptop, modem, or other auxiliary device
through a serial cable with an RJ-45 connector.
—Connects the Routing Engine to a system console through a serial cable
CONSOLE
with an RJ-45 connector.
—Connects the Routing Engine through an Ethernet connection
ETHERNET or MGMT
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 support
10-Mbps or 100-Mbps connections. Two small LEDs on the right of the port indicate
the connection in use: The LED on the left indicates speed—green for 1000-Mbps,
yellow for 100-Mbps and when the LED is dark, it indicates 10-Mbps speed. The LED
on the right indicates activity—flashing green when packets are passing through the
port.

Routing Engine Boot Sequence

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. The disk from which the
router boots is called the primary boot device, and the other disk is the alternate boot
device.
NOTE: If the router boots from an alternate boot device, a yellow alarm lights
the LED on the router's craft interface.
Booting in a RE-S-X6-64G Routing Engine follows this sequence—the USB device, SSD1,
SSD2, and LAN. SSD1 is the primary boot device. Boot sequence is tried twice for SSD1
and SSD2.
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 router without interruption. For more information about graceful switchover, see the
Junos OS Administration Library.
NOTE: If two Routing Engines are installed, they must both be the same
hardware model.
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