System as an Authoritative NTP Server

The NTP server can operate in master mode to serve time using the local clock when it has lost synchronization. Serving local clock can be enabled using the master command. In this mode, the NTP server stratum number is set to the configured stratum number. When the master command is configured and the device was never synchronized with an upstream time server and the clock setting is invalid, the server will respond to the client's request with the stratum number set to 16. While the device is operating in the master mode and serving the local clock as the reference time, if synchronization with the upstream server takes place it will calibrate the local clock using the NTP time. The stratum number will switch to that of the synchronized source +1. When synchronization is lost, the device switches back to local clock time with the stratum number as specified manually (or the default).

Note: Local time and time zone have to be configured before configuring the master command.

The following scenarios are observed when the master command is not configured and the NTP upstream servers are configured:

  • If the synchronization with the NTP server/peer is active, the system clock is synchronized, and the reference time is the NTP time.
  • If the NTP server/peer is configured but not reachable and if the local clock is valid, the server will respond to client's request with the stratum number set to 16.
  • If there is no NTP server/peer configured and if the local clock is valid, the server will respond to client's request with the stratum number set to 16.
  • If there is no NTP server/peer configured and if the local clock is invalid, the system clock is not synchronized.
  • By default, the system configures the RUCKUS NTP server (ntp.ruckuswireless.com) when no NTP servers are configured or when NTP is disabled. The system uses this server as a fallback time source and does not display it in the running configuration. If you remove the default NTP server using the no server ntp.ruckuswireless.com command, the change persists across reloads. The system does not restore the default server after a reload.

The following scenarios are observed when the master command is configured and the NTP upstream servers are also configured:

  • If the synchronization with the time server/peer is active, system clock is synchronized and the reference time is the NTP time. If the NTP server/peer is configured but not reachable, the system clock is synchronized. If the local time is valid then the reference time is the local clock time.
  • If the NTP server/peer is not configured, the system clock is synchronized. If the local clock is valid, then the reference time is the local clock time.
  • If the NTP server/peer is not configured and the local clock is invalid, system clock is not synchronized.
Note: Use the master command with caution. It is very easy to override valid time sources using this command, especially if a low stratum number is configured. Configuring multiple machines in the same network with the master command can cause instability in timekeeping if the machines do not agree on the time.
Parent topic: NTP server