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Understanding Redundancy of QFX3500 Device Components and Functionality

The following hardware components provide redundancy on a QFX3500 device:

  • Power supplies—The QFX3500 device has one or two power supplies. Each power supply provides power to all components in the device. If two power supplies are installed, the two power supplies provide full power redundancy to the device. If one power supply fails or is removed, the second power supply balances the electrical load without interruption.

    To provide power redundancy to the system both power supplies must be installed. Connect power source feed A to one power supply and power source feed B to the second power supply.


    Do not connect feed A and feed B to the same power supply input terminal.

  • Cooling system—The QFX3500 device has two fan trays. Additional cooling is provided by two fan modules on the management board. If a fan module on a fan tray or management board fails and is unable to keep the QFX3500 device within the desired temperature thresholds, chassis alarms occur and the QFX3500 device may shut down.