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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, via 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:
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T1 — The time at which the original request was sent by the client.
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T2 — The time at which the original request was received by the server.
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T3 — The time at which the server sent a reply.
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T4 — The time at which the client received the server's reply.
Polling for Unicast Time Information
Polling for Unicast information is used for polling a server for which the IP address is known. T1 -
T4 are used to determine the server time. This is the preferred method for synchronizing switch
time.
Polling for Anycast Time Information
Polling for Anycast information is used when the server IP address is unknown. The first anycast
server to return a response is used to set the time value. Time levels T3 and T4 are used to
determine the server time. Using Anycast time information for synchronizing switch time is
preferred to using Broadcast time information.
Broadcast Time Information
Broadcast information is used when the server IP address is unknown. When a Broadcast message
is sent from an SNTP server, the SNTP client listens for the response. The SNTP client neither
sends time information requests nor receives responses from the Broadcast server.
MD5 (Message Digest 5) Authentication safeguards switch synchronization paths to SNTP servers.
MD5 is an algorithm that produces a 128-bit hash. MD5 is a variation of MD4, and increases MD4
security. MD5 verifies the integrity of the communication, authenticates the origin of the
communication.
Click System→ SNTP in the tree view to open the SNTP page.
Defining SNTP Global Parameters
The SNTP Global Settings page provides information for defining SNTP parameters globally. To
open the SNTP Global Settings page, click System → SNTP→ Global Settings in the tree view.
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Configuring System Information
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