Sntp Modes; Configuring System Time; Selecting Source Of System Time - Cisco Small Business 200 Series Administration Manual

Administration: Time Settings

SNTP Modes

The DHCP server must supply DHCP option 100 in order for dynamic time zone configuration
NOTE
to take place.
SNTP Modes
The device can receive system time from an SNTP server in one of the following ways:
• Client Broadcast Reception (passive mode)—SNTP servers broadcast the time, and the device
listens to these broadcasts. When the device is in this mode, there is no need to define a Unicast
SNTP server.
• Client Broadcast Transmission (active mode)—The device, as an SNTP client, periodically requests
SNTP time updates. This mode works in either of the following ways:
- SNTP Anycast Client Mode—The device broadcasts time request packets to all SNTP servers in
the subnet, and waits for a response.
- Unicast SNTP Server Mode—The device sends Unicast queries to a list of manually-configured
SNTP servers, and waits for a response.
The device supports having all of the above modes active at the same time and selects the best system
time received from an SNTP server, according to an algorithm based on the closest stratum (distance from
the reference clock).

Configuring System Time

Selecting Source of System Time

Use the System Time page to select the system time source. If the source is manual, you can enter the time
here.
!
CAUTION
Cisco Small Business 200 Series Smart Switch Administration Guide
If the system time is set manually and the device is rebooted, the manual time
settings must be reentered.
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