Dell Networking N4032 Configuration Manual page 38

If either of the following screens appear, they are simply notifying the user that the network has been lost.
This is only temporarily while the stack reloads.
Click OK if prompted with the above screen. Rebooting the stack may take a few minutes longer than a
single switch. After reload, the firmware upgrade is complete. To validate each switch, login again to the
Web UI of the stack Master, and then go to System > File Management > Active Images.
Notice that as the backup versions become active, the previous active versions now become the backup.
This allows the administrator to toggle back to the previous image if needed for troubleshooting. Going
back to the previous version is rarely ever used and must be done with extreme caution if the newer
firmware has been running a long time with several configuration changes since the initial upgrade. Newer
firmware can have dozens of valuable bug fixes that will not be there on the older firmware.
38 Stacking Dell Networking Switches: N4032, N4032F, N4064, N4064F