User`s manual

User’s Manual 53
Chapter 4: Configuring SNTP
You can configure the switch to send time synchronization requests to specific time servers (For example,
client mode), update its clock based on broadcasts from time servers, or use both methods. When both
methods are enabled, the switch will update its clock using information broadcast from time servers, but will
query the specified server(s) if a broadcast is not received within the polling interval.
4.1 SNTP Attributes
SNTP Client – Configures the switch to operate as an SNTP unicast client. This mode requires at least one
time server to be specified in the SNTP Server field. (Default: Disabled)
SNTP Broadcast Client – Configures the switch to operate as an SNTP broadcast client. This mode requires
no other configuration settings; the switch will obtain time updates from time server broadcasts (using the
multicast address 224.0.1.1). (Default: Disabled)
SNTP Poll Interval – Sets the interval between sending requests for a time update from a time server when
set to SNTP Client mode. (Range: 16-16284 seconds; Default: 16 seconds)
SNTP Server – In unicast mode, sets the IP address for up to three time servers. The switch attempts to
update the time from the first server, if this fails it attempts an update from the next server in the sequence.
Configuring Switch Using the Web or CLI
Web
Click SNTP – Configuration. Modify any of the required parameters, and click Apply.
CLI
This example configures the switch to operate as an SNTP broadcast client.
Console(config)#sntp client
Console(config)#sntp poll 16
Console(config)#sntp server 10.1.0.19 137.82.140.80 128.250.36.2
Console(config)#sntp broadcast client
Console(config)#
4.2 Setting the Time Zone
SNTP uses Coordinated Universal Time (or UTC, formerly Greenwich Mean Time, or GMT) based on the
time at the Earth’s prime meridian, zero degrees longitude. To display a time corresponding to your local
time, you must indicate the number of hours and minutes your time zone is east (before) or west (after) of
UTC.