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Maintaining the T640 Host Subsystem



For optimum router performance, verify the condition of the host subsystem. The host subsystem comprises a Routing Engine and up to two adjacent control boards functioning together.


On a regular basis:

  • Check the host subsystem LEDs (HOST0 and HOST1) on the craft interface. If the red HOST0 FAIL or HOST1 FAIL LED is lit, look at the LCD to get more information about the cause of the problem. For more information about the LEDs and the display, see T640 Craft Interface Description.

    During normal operations:

    • The green host subsystem OK LED on the craft interface is lit.

    • The red host subsystem FAIL LED on the craft interface is not lit.

  • Check the LCD on the craft interface to view information about the status of the Routing Engines and control boards.