System Time Options - Cisco SF 300-08 Administration Manual

System Time

System Time Options

System Time Options
Cisco Small Business 300 Series Managed Switch Administration Guide
System time can be set manually by the user or dynamically by using an SNTP
server. If an SNTP server is chosen, the manual time settings are overwritten when
communications with the server is established.
As part of the boot process, the switch always configures the time, time-zone, and
DST in some way, either from DHCP, from SNTP, from values set manually, or if all
else fails from the factory defaults.
Time
The following methods are available for obtaining or setting the time on the switch:
• SNTP that ensures accurate network time synchronization of the switch up
to the millisecond by using an SNTP server for the clock source.
Without synchronized time, accurately correlating log files between
NOTE
devices is difficult, even impossible. We recommend that you use SNTP for
the clock source.
• Manual entry of the system time by the user.
• Entry of the time by the computer that accesses the switch through the
device configuration utility. If this feature is enabled, the switch uses the
system time from the configuring computer, unless the time has been
configured on the switch manually by the user or SNTP server support is not
available or enabled.
Receiving the time from the computer configuring the switch should
NOTE
be the last resort, such as after a power outage and no other time source is
available.
Time Zone and Daylight Savings Time (DST)
The Time Zone and DST can be set on the switch in the following ways:
• Dynamic configuration of the switch through a DHCP server, where:
- Dynamic DST, when enabled and available, always takes precedence
over the manual configuration of DST.
- If the server supplying the source parameters fails or dynamic
configuration is disabled by the user, the manual settings are used.
- Dynamic configuration of the time zone and DST continues after the IP
address lease time has expired.
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