Network Time Protocol overview

Network Time Protocol (NTP) maintains uniform time across all devices in a network. The NTP commands support the configuration of an external time server to maintain synchronization among all local clocks in a network.

To keep the time in your network current, it is recommended that each device have its time synchronized with at least one external NTP server.

Date and time settings

Extreme devices maintain the current date and time inside a battery-backed real-time clock (RTC) circuit. Date and time are used for logging events. Device operation does not depend on the date and time; a device with incorrect date and time settings can function correctly. However, because the date and time are used for logging, error detection, and troubleshooting, you should set them correctly.

Time zone settings

The time zone settings have the following characteristics:

The setting automatically adjusts for Daylight Savings Time.
Changing the time zone on a device updates the local time zone setup and is reflected in local time calculations.
By default, all devices are in the Greenwich Mean Time (GMT) time zone (0,0).
System services that have already started will reflect the time zone changes only after the next reboot.
Time zone settings persist across failover for high availability.
Time zone settings are not affected by NTP server synchronization.