Monitoring Redundant Control Boards

You monitor and maintain redundant Control Boards installed in the M320 router, T320 router, or T640 routing node to ensure that there is no interruption of functions such as the following:

• Router component monitoring and control for failure and alarm conditions
• Component power-up and power-down control
• Redundant Routing Engine and Control Board mastership control
• Flexible PIC Concentrator (FPC) error detection and reset control
• SONET clock source generation and monitoring
• SONET reference clock monitoring (from the FPC and BIT interfaces)
• I²C controller monitoring
• Fan speed monitoring and control

For more information about monitoring a single Control Board, see Monitoring the Control Board.

Table 119 provides a checklist of tasks you perform to monitor redundant Control Boards.

Table 119: Checklist for Monitoring Redundant Control Boards

Monitor Redundant Control Board Tasks	Command or Action
Understanding Redundant Control Boards
Displaying Redundant Control Board Hardware Information	show chassis hardware
Displaying Redundant Control Board Mastership
Check the Redundant Control Board Environmental Status	show chassis environment cb
Check the Redundant Control Board Status from the Craft Interface	show chassis craft-interface
Check the Redundant Control Board LED Status	Examine the LEDs on the Control Board faceplate.
Switching Control Board Mastership	Press the Control Board offline button on the component faceplate.
Checking the Control Board Alarms	See Checking the Control Board Alarms. For conditions that trigger Control Board alarms, see Display the Current Router Alarms.
Replacing a Control Board	Determine whether the host subsystem is functioning as master or as backup by using the show chassis routing-engine command. Take the host subsystem offline if the Control Board is master by using the request chassis routing-engine master switch command. Replace the Control Board with a known working one. Check the Control Board status by examining the LEDs on the Control Board faceplate, or by using the show chassis hardware command.
Returning the Control Board	Locate the Control Board serial number ID label. See Return the Failed Component or the appropriate hardware guide.