The switch must have access to the current time to verify that certificates have not expired. To configure the switch to request time updates from the network time server, click Global - NTP and click the Enable NTP box. Enter the name of your network time source in the provided boxes. You may also set an hour interval to specify how often to request time updates. If the interval is set to 0, requests will only be made during appliance startup or when changes to the Global - NTP menu are made.