Routing Engine Boot Sequence; Mx480 Routing Engine Leds - Juniper MX480 Hardware Manual

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.
SEE ALSO
MX480 Router Description | 27

MX480 Routing Engine LEDs | 68

MX480 Host Subsystem Description | 63
MX-Series Switch Control Board (SCB) Description | 170

MX480 Routing Engine LEDs

Each 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 24 on page 70 describe the functions of the Routing Engine LEDs.
Table 23 on page 69 and
68