Why is there no Firmware Upgrade button on the Maintenance->Upgrade page?
If, due to internet connectivity problem, a firmware upgrade procedure fails in the middle of the downloading and the 2211 has not been rebooted, the Upgrade button will not be available. You can solve this problem by rebooting the 2211 and going through the normal firmware upgrade again. Another option is to factory reset and reboot the unit. The Upgrade button also may not work properly if Javascript is disabled by the browser.