To enable authentication, you must configure either unicast or broadcast mode. After authentication is enabled, changing the mode from unicast to broadcast or vice versa is not allowed; you must disable authentication and then change the mode.

To set the SNTP mode or change from one mode to the other, enter the appropriate command.




This command configures SNTP, including specifying whether the switch operates in broadcast or unicast mode.



The Default. SNTP does not operate, even if specified by the Menu interface Time Sync Method parameter or the CLI timesync command.


Directs the switch to poll a specific server for SNTP time synchronization. Requires at least one server address.


Directs the switch to acquire its time synchronization from data broadcast by any SNTP server to the network broadcast address. The switch uses the first server detected and ignores any others. However, if the Poll Interval expires three times without the switch detecting a time update from the original server, the switch accepts a broadcast time update from the next server it detects.

Poll interval (seconds)

In Unicast Mode: Specifies how often the switch polls the designated SNTP server for a time update.

In Broadcast Mode: Specifies how often the switch polls the network broadcast address for a time update.

Value is between 30 to 720 seconds.

Server Address

Used only when the SNTP Mode is set to Unicast. Specifies the IP address of the SNTP server that the switch accesses for time synchronization updates. You can configure up to three servers; one using the menu or CLI, and two more using the CLI.

Server Version

Specifies the SNTP software version to use and is assigned on a per-server basis. The version setting is backwards-compatible. For example, using version 3 means that the switch accepts versions 1 through 3. Default: 3; range: 1 to 7.


Specifies the order in which the configured servers are polled for getting the time.

Value is between 1 and 3.


For switches that have a separate out-of-band management port, specifies that SNTP traffic goes through that port. (By default, SNTP traffic goes through the data ports.)

sntp broadcast|unicast output

switch# sntp broadcast
switch# sntp unicast