Chassis And Interface Alarm Messages; Alarm Relay Contacts; Craft Interface Leds - Juniper MX480 Hardware Manual

You enter CLI commands on one or more external management devices connected to ports on the Routing
Engine.
For information about using the CLI to troubleshoot the Junos OS, see the appropriate Junos OS
configuration guide.

Chassis and Interface Alarm Messages

When the Routing Engine detects an alarm condition, it lights the red or yellow alarm LED on the craft
interface as appropriate. To view a more detailed description of the alarm cause, issue the
show chassis alarms command:
user@host> show chassis alarms
There are two classes of alarm messages:
Chassis alarms—Indicate a problem with a chassis component such as the cooling system or power
supplies.
Interface alarms—Indicate a problem with a specific network interface.

Alarm Relay Contacts

The craft interface has two alarm relay contacts for connecting the router to external alarm devices.
Whenever a system condition triggers either the red or yellow alarm on the craft interface, the alarm relay
contacts are also activated. The alarm relay contacts are located on the upper right of the craft interface.

Craft Interface LEDs

The craft interface is the panel on the front of the router located above the DPC cards that contains LEDs
and buttons that allow you to troubleshoot the router.
LEDs on the craft interface include the following:
Alarm LEDs—One large red circular LED and one large yellow triangular LED, located on the upper right
of the craft interface, indicate two levels of alarm conditions. The circular red LED lights to indicate a
critical condition that can result in a system shutdown. The triangular yellow LED lights to indicate a less
severe condition that requires monitoring or maintenance. Both LEDs can be lit simultaneously. A
condition that causes an alarm LED to light also activates the corresponding alarm relay contact on the
craft interface.
Host subsystem LEDs—Three LEDs, MASTER, ONLINE, and OFFLINE, indicate the status of the host
subsystem. A green MASTER LED indicates that the host is functioning as the master. The ONLINE LED
indicates that the host is online. The OFFLINE LED indicates that the host is installed but the routing
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