System Operation as an NTP Server

The NTP server supports both unicast (user-to-user addressing protocol) and broadcast modes. Depending on the server configuration you choose, the system functions in different ways:

• When the system is configured as a unicast NTP server, it synchronizes clients to its own clock by responding to NTP requests from clients as follows:
  1. Swaps the destination and source addresses in the request packet.
  2. Sets all timestamps and NTP attributes in the packet.
  3. Returns the packet to the client.
• When the system is configured as a broadcast NTP server, it periodically sends NTP time synchronization messages to the local network broadcast address (255.255.255.255). The broadcast server would also respond to any NTP unicast requests from clients.

If the system is configured both as an NTP client and an NTP server, the system effectively synchronizes its clients to its master’s clock. If the system is configured as an NTP server but not an NTP client, the system synchronizes its clients to its own clock, which can be set by the clock commands.

Note: When the system is not configured as either an NTP client or an NTP server, it responds to NTP requests with an invalid stratum number.

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