NTP poll interval

Each Network Time Protocol (NTP) association supports a poll process that runs at regular intervals to construct and send packets in symmetric, client, and broadcast server associations. It runs continuously, whether or not servers are reachable in order to manage the clock filter and reach register.

The polling interval is reported in seconds. The interval usually starts with a minimum of 64-second poll intervals. The RFC specifies that no more than one NTP transaction per minute is needed in order to synchronize two machines. As NTP becomes stable between a client and a server, the poll interval may increase in small steps from 64 seconds up to 1024 seconds and generally stabilizes somewhere in between.

But, this value dynamically changes, based on the network conditions between the client and the server and the loss of NTP packets. If a server is unreachable for some time, the poll interval is increased in steps to 1024 seconds in order to reduce network overhead.

It is not possible to adjust the NTP poll interval on a router, because the internal is determined by heuristic algorithms.