User Manual

S350 Series 24-Port (PoE+) and 48-Port Gigabit Ethernet Smart Switches
Configure System Information User Manual44
7. Next to Client Mode, select the mode of operation of the SNTP client:
• Unicast. SNTP operates in a point-to-point way. A unicast client sends a request to a
designated server at its unicast address and expects a reply from which it can
determine the time and, optionally, the round-trip delay and local clock offset relative
to the server.
• Broadcast. SNTP operates in the same manner as multicast mode but uses a local
broadcast address instead of a multicast address. The broadcast address provides a
single-subnet scope while a multicast address provides an Internet-wide scope.
The default value is Disable.
8. If the SNTP client mode is Unicast, you must add the IP address or DNS name of one or
more SNTP servers that the switch can poll.
For more information, see Configure an SNTP Server on page 47.
9. In the Port field, specify the local UDP port that the SNTP client receives server packets on.
The allowed range is 1025 to 65535 and 123. The default value is 123. When the default
value is configured, the actual client port value used in SNTP packets is assigned by the
switch.
10. In the Unicast Poll Interval field, specify the number of seconds between unicast poll
requests expressed as a power of 2. The allowed range is 6 to 10. The default value is 6.
11. In the Broadcast Poll Interval field, specify the number of seconds between broadcast poll
requests expressed as a power of 2.
Broadcasts received prior to the expiry of this interval are discarded. The allowed range is
6 to 10. The default value is 6.
12. In the Unicast Poll Timeout field, specify the number of seconds to wait for an SNTP
response to a unicast poll request.
The allowed range is 1 to 30. The default value is 5.
13. In the Unicast Poll Retry field, specify the number of times to retry a unicast poll request to
an SNTP server after the first time-out before the switch attempts to use the next configured
server.
The allowed range is 0 to 10. The default value is 1.
14. In the Time Zone Name field, specify the acronym for a time zone.
You can also specify the number of hours and number of minutes that the time zone is
different from the Coordinated Universal Time (UTC). The time zone can affect the
display of the current system time. The default value is UTC.
Note: When you use an SNTP or NTP time server to update the switch’s
clock, the time data received from the server is based on the UTC,
which is the same as Greenwich Mean Time (GMT). However, this
might not be the time zone in which the switch is located.
15. In the Offset Hours field, specify the number of hours that the time zone is different from the
UTC.