82 Configuring System InformationPolling for Anycast Time InformationPolling for Anycast information is used when the server IP address is unknown. The first anycast serverto return a response is used to set the time value. Time levels T3 and T4 are used to determine theserver time. Using Anycast time information for synchronizing switch time is preferred to usingBroadcast time information.Broadcast Time InformationBroadcast information is used when the server IP address is unknown. When a broadcast message is sentfrom an SNTP server, the SNTP client listens for the response. The SNTP client neither sends timeinformation requests nor receives responses from the Broadcast server.MD5 (Message Digest 5) Authentication safeguards switch synchronization paths to SNTP servers. MD5is 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 ParametersThe SNTP Global Settings page provides information for defining SNTP parameters globally. To openthe SNTP Global Settings page, click System → SNTP→ SNTP Global Settings in the tree view.Figure 6-7. SNTP Global Settings• Poll Interval (60-86400) — Defines the interval (in seconds) at which the SNTP server is polled forUnicast information.• Receive Broadcast Servers Updates — Polls the SNTP servers for Broadcast server time information onthe selected interfaces.
