AR Fast SNTP v0.10.3 — Windows x64

AR Fast SNTP v0.10.3 — Windows x64

A performance and network-recovery refinement built directly on the tested v0.10.2 SNTP Windows Studio. The public download remains one Inno Setup executable: ARFastSNTP-Setup-Windows-x64.exe, plus a separate tiny .sha256 integrity file. No second installer, portable ZIP, separate service package or .NET runtime is required.

Changes from v0.10.2

• Fast validated confirmation: After an initial coherent burst of three independently originated SNTP exchanges, the next confirmation probe is due after 750 ms rather than a generic three-second stable polling interval. A new valid Mode 4 response must still agree within the existing 250 ms spread threshold.
• Deadline-aware supervisor: If the next source probe is already due after other slow/unreachable peers complete, the worker no longer inserts another unconditional one-second sleep.
• Network-notification resilience: Irrelevant Windows network notifications no longer invalidate healthy source measurements when the observed IPv4 adapter/address/gateway fingerprint has not materially changed.
• No protocol protection removed: Originate binding, server mode/stratum/leap, RTT limits, election consensus, clock-epoch and stale sample safeguards, NTP RATE/DENY/RSTR limits and the single Windows clock writer remain enforced.
• All existing v0.10.2 functionality remains: bounded polling (up to 4 concurrent probes), up to 16 IPv4 servers, fast OFF→ON, Ethernet recovery, persistent Windows Service, compact Avalonia Studio, RTT tooltips, status history and JSON diagnostics.

Real Windows feedback and CI evidence

User-reported acceptance of the tested source commit 103dc9af8dfd4aed687aac1c23b994b5c91c702a: roughly one second for clock correction and roughly six seconds to recover and start syncing after the LAN cable was reconnected. These are observations on that test PC, not a service-level guarantee; actual performance depends on interface/route readiness, UDP replies and source consensus.

The tested engine commit passed Windows CI #38093326129. The final public v0.10.3 installer is built and verified again by the post-merge main Windows CI; inspect its workflow and source SHA in this release before deployment.

Install / upgrade

Download only the official ARFastSNTP-Setup-Windows-x64.exe asset and its companion .sha256 file from this GitHub Release. Verify checksum:

Get-FileHash .\ARFastSNTP-Setup-Windows-x64.exe -Algorithm SHA256

Run the Inno installer as administrator on an authorized test/engineering PC. It uses the existing application identity so it can upgrade a previous installation; an existing %ProgramData%\ARFastSNTP\peers.json peer catalog is preserved on normal upgrades. Subsequent Add/Delete/Enable/Disable in Studio does not reinstall the Windows Service or prompt for UAC.

Standard installation permits Windows time correction after source validation. For monitor-only lab testing, run the installer with /LABSYNC=0. Uninstall using Windows Settings → Apps → Installed apps → AR Fast SNTP.

Safety and limits

The installer is unsigned; Windows SmartScreen may warn. Confirm official repository/release origin and SHA-256. Do not disable antivirus, firewall, or Windows policies to bypass warnings.

Not certified for production SCADA, SOE, historian, GPS reference or other critical timing systems. Large-step, independent GPS failover, 24-hour soak, code signing and upgrade-rollback certification remain documented under post-release hardening Issue #2. This is an IPv4 unicast SNTP client, not a full RFC 5905 NTP discipline implementation; ARSAS same-host Npcap RAW delivery is not claimed resolved.

Source: https://github.com/masarray/arfast-sntp · License: GPL-2.0-or-later (LICENSE/NOTICE included in the installer).