Monitoring the Control Board

You monitor and maintain the Control Boards that provide control and monitoring functions for the router. These functions include determining Routing Engine mastership, controlling power, performing reset and SONET clocking for the other router components, monitoring and controlling fan speed, and monitoring system status using I²C controllers. (See Table 71.)

For information on monitoring the Control Boards, see Monitoring the Host Subsystem.

Table 71: Checklist for Monitoring the Control Board

Monitor the Control Board Tasks	Command or Action
Understanding the Control Board M320 Router Control Board T320 Router Control Board T640 Routing Node Control Board M320 Router, T320 Router, and T640 Routing Node Control Board Location
Monitoring the Control Board Status
Check the Control Board Environmental Status	show chassis environment cb
Check the Control Board Status from the Craft Interface	show chassis craft-interface Check the LEDs on the Control Board faceplate. Check the Host Subsystem LEDs on the T320 router and the T640 routing node craft interface.
Checking the Control Board Alarms
Display Control Board Alarms	show chassis alarms For conditions that trigger M320 router alarms, see Table 25. For conditions that trigger T320 router alarms, see Table 26. For conditions that trigger T640 routing node alarms, see Table 27.
Check the Control Board LEDs	Look at the LEDs on the Control Board faceplate.
Display Control Board Error Messages in the System Log File	show log messages | match cb
Display Control Board Error Messages in the Chassis Daemon Log File	show log chassisd | match cb
Verifying Control Board Failure
Check the Control Board Connection	Make sure that the Control Board is properly seated in the midplane. Ensure that none of the pins are bent. Check the thumbscrews on the ejector locking tabs.
Check the Control Board Fuses	The fuses for the Control Boards are located in the rear of the midplane behind the power supply in slot PEM0.
Perform a Control Board Swap Test	Take the host subsystem offline if the Control Board is master. Replace the Control Board with one that you know works. Bring the Control Board online. Check the Control Board status.
Display the Control Board Hardware Information	show chassis hardware
Locate the Control Board Serial Number ID Label	Look on the bottom of the left side of the Control Board.
Returning the Control Board	Follow the procedure in the appropriate hardware guide.