Dell Networking | Basic Troubleshooting for Unresponsive Switches (No Boot - No Power)

Dell Networking | Basic Troubleshooting for Unresponsive Switches (No Boot - No Power)

1. Look for visual and auditory evidence of switch operation:

Visual:

1. 1. Link LEDs: Illuminated link LEDs indicate that the switch is up and passing traffic.
   2. System LED Indicator: The color of the system LED can indicate critical or noncritical system errors.
   3. Fan/PSU LEDs: Unlit Fan/PSU LEDs can indicate a faulty component that may inhibit the switch from booting.

Auditory:

1. 1. A lack of sound from the switch fans or Power Supply (PSU) fans may indicate a no boot - no power situation.
   2. A constant state of excessively loud fans may indicate that the switch is stuck somewhere in the boot process. A console connection can then be used to validate the specific operation in the boot process that is causing the switch to hang.

2. Establish a serial console connection to the switch using a known working cable.

1. Most Dell switch platforms use the following console settings:
   • 115200 baud/speed (try 9600 if 115200 does not yield a response)
   • No parity
   • Eight data bits
   • One stop bit
   • No flow control
2. If using a switch's Micro USB-B port for console connection, ensure that the customer has the appropriate USB drivers for their computer platform:
   • Windows: https://www.silabs.com/documents/public/software/CP210x_Universal_Windows_Driver.zip
   • MacOS:  https://www.silabs.com/documents/public/software/Mac_OSX_VCP_Driver.zip
3. If the initial console connection attempt is unsuccessful, try establishing a console connection to a different switch of the same model (if possible) or use a different client to determine the device responsible for the console connection failure. If the second console connection attempt is successful, this reduces the likelihood that the client/cable caused the serial connection failure and points to a hardware failure of the switch.

3. Once a serial console connection is established, observe the switch's behavior to determine why the switch is "unresponsive":

1. The presence of EXT4-fs-related and other partition errors may indicate an issue with the file mounting system or the SSD itself. If possible, attempt a complete reimaging of the switch, including any available SSD firmware updates.
2. If the switch has accidentally booted into ONIE: Install OS mode, check to see if the NOS partitioning is still present on the switch:
   1. Use the appropriate command to stop the flood of connection attempts from the ONIE discover process.

      ONIE:/ # onie-stop
      
      -----or-----
      
      ONIE:/ # onie-discovery-stop

   2. Use the ONIE Extensible Firmware Interface Boot Manager command to view the switch's current boot order.

      ONIE:/ # efibootmgr

      1. If the switch's NOS is present in the list of boot options, but not the first entry in the BootOrder list, use the ONIE Extensible Firmware Interface Boot Manager command with the appropriate modifiers as shown below to restore the correct boot order preference.

         ONIE:/ # efibootmgr -o [boot order]

         ONIE:/ # efibootmgr
         BootCurrent: 0000
         Timeout: 3 seconds
         BootOrder: 0000,0001,0004,0003,0002
         
         Boot0000* ONIE: Open Network Install Environment
         Boot0001* OS10
         Boot0002* EDA-DIAG
         Boot0003* Hard Drive
         Boot0004* UEFI: Built-in EFI Shell
         
         ONIE:/ # efibootmgr -o 0001,0000,0004,0003,0002
         
         BootCurrent: 0000
         Timeout: 3 seconds
         BootOrder: 0001,0000,0004,0003,0002
         
         Boot0000* ONIE: Open Network Install Environment
         Boot0001* OS10
         Boot0002* EDA-DIAG
         Boot0003* Hard Drive
         Boot0004* UEFI: Built-in EFI Shell

      2. If the switch's NOS is not present in the list of boot options, perform a reinstallation of the NOS and update any firmware (ONIE, SSD, FW) as appropriate.
3. If the switch is missing its NOS or ONIE (or both), fails to properly boot into NOS or ONIE, or only boots into GRUB, perform the ONIE Recovery steps described in Knowledge Article Dell Networking- How to Create an ONIE Recovery Live Disk to restore ONIE using the ONIE Recovery ISO image, then use the restored ONIE shell to continue with a standard reinstallation of NOS and applicable switch firmware (ONIE/SSD/FW).

4. If a serial console connection cannot be established, or if the corrective actions listed in Step 3 fail to properly restore the switch to normal operating condition, contact Dell Support to troubleshoot.