Management and Configuration Guide K/KA/KB.15.15

• Press à to move the cursor to the Server Address field.
• Enter the IP address of the TimeP server you want the switch to use for time synchronization.
NOTE: This step replaces any previously configured TimeP server IP address.
• Press à to move the cursor to the Poll Interval field, then go to step 6.
6. In the Poll Interval field, enter the time in minutes that you want for a TimeP Poll Interval.
7. Select [Enter] to return to the Actions line, then select [S] (for Save) to enter the new time protocol
configuration in both the startup-config and running-config files.
About SNTP time synchronization
SNTP provides two operating modes:
• Broadcast mode
The switch acquires time updates by accepting the time value from the first SNTP time broadcast
detected. (In this case, the SNTP server must be configured to broadcast time updates to the
network broadcast address; see the documentation provided with your SNTP server application.)
Once the switch detects a particular server, it ignores time broadcasts from other SNTP servers
unless the configurable Poll Interval expires three consecutive times without an update received
from the first-detected server.
NOTE: To use Broadcast mode, the switch and the SNTP server must be in the same subnet.
• Unicast mode
The switch requests a time update from the configured SNTP server. (You can configure one
server using the menu interface, or up to three servers using the CLI sntp server command.)
This option provides increased security over the Broadcast mode by specifying which time
server to use instead of using the first one detected through a broadcast.
About SNTP: Selecting and configuring
Table 1 (page 66) shows the SNTP parameters and their operations.
Table 1 SNTP parameters
OperationSNTP parameter
Used to select either SNTP, TIMEP, or None as the time synchronization
method.
Time Sync Method
SNTP Mode
The Default. SNTP does not operate, even if specified by the Menu interface
Time Sync Method parameter or the CLI timesync command.
Disabled
Directs the switch to poll a specific server for SNTP time synchronization.
Requires at least one server address.
Unicast
Directs the switch to acquire its time synchronization from data broadcast
by any SNTP server to the network broadcast address. The switch uses the
Broadcast
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.
In Unicast Mode: Specifies how often the switch polls the designated SNTP
server for a time update.
Poll Interval (seconds)
In Broadcast Mode: Specifies how often the switch polls the network broadcast
address for a time update.
Value is between 30 to 720 seconds.
66 Time Protocols