NETGEAR AV Line M4250 GSM4210PX 8-Port Gigabit PoE+ Compliant Managed AV Switch with SFP (220W) - Manual (Page 71)

Table 16. SNTP global status information (Continued)
Description Field
The number of current valid unicast server entries configured for this client. Unicast Server Current
Entries
The number of unsolicited broadcast SNTP messages that were received and
processed by the SNTP client since the last reboot.
Broadcast Count
Configure SNTP servers
SNTP assures accurate time synchronization for network device clock, up to the
millisecond. Time synchronization is performed by a network SNTP server. The switch
operates as an SNTP client only and does provide time services to other devices.
Time sources are established by stratums. Stratums define the accuracy of the reference
clock. The higher the stratum (zero is the highest), the more accurate the clock. The
switch receives time from stratum 1 or stratum 0 devices because the switch itself is a
stratum 2 device.
The following are examples of stratums:
• Stratum 0: A real-time clock is used as the time source, for example, a GPS system.
• Stratum 1: A server that is directly linked to a stratum 0 time source is used. Stratum
1 time servers provide primary network time standards.
• Stratum 2: The time source is distanced from the stratum 1 server over a network
path. For example, a stratum 2 server receives the time over a network link, through
NTP, from a stratum 1 server.
Information received from SNTP servers is evaluated based on the time level and server
type.
SNTP time definitions are assessed and determined by the following time levels:
• T1: Time that the original request was sent by the client.
• T2: Time that the original request was received by the server.
• T3: Time that the server sent a reply.
• T4: Time that the client received the server's reply.
The switch can poll unicast server types for the server time. The switch polls for unicast
information to detect a server for which the IP address is known. SNTP servers that you
configure on the switch are the only ones that are polled for synchronization information.
T1 through T4 are used to determine the server time. This is the preferred method for
Main User Manual 71 Configure Switch System
Information
AV Line of Fully Managed Switches M4250 Series Main User Manual