Juniper Networks MX480 - Manual (Page 57)

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.
• CONSOLE —Connects the Routing Engine to a system console through a serial 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 support
10-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.
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.
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 System Basics Configuration Guide.
NOTE: If two Routing Engines are installed, they must both be the same
hardware model.
Related
Documentation
MX480 Router Description on page 3 •
• MX480 Routing Engine LEDs on page 36
• MX480 Host Subsystem Description on page 26
• MX480 Switch Control Board (SCB) Description on page 26
33 Copyright © 2013, Juniper Networks, Inc.
Chapter 2: MX480 Hardware Components