User guide

82 Configuring System Information
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→ 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 for
Unicast information.
•
Receive Broadcast Servers Updates — Polls the SNTP servers for Broadcast server time information on
the selected interfaces.