NtpServerOptions Class

The limit is approximate: source addresses are mapped onto a fixed number of buckets so that memory cannot grow with the number of distinct (and easily spoofed) source addresses seen, and colliding addresses share a budget.

Rate limiting is measured against the real system clock rather than NtpServerOptions.TimeProvider, so that a simulated or frozen clock cannot disable it or wedge it permanently.

Clients use this as the error bound on the offset they compute. Zero claims a perfectly accurate clock, which is never true, so the default is a deliberately conservative bound for an undisciplined software clock. Lower it if the underlying NtpServerOptions.TimeProvider is disciplined and you know its accuracy.

Stratum 1 claims a directly attached reference clock such as GPS. A server answering from NtpServerOptions.TimeProvider has no such clock, so the honest value is 2 or higher; set NtpServerOptions.ReferenceIdentifier to match if you do attach one.