AR Fast SNTP v0.10.4 — Windows x64

AR Fast SNTP v0.10.4 — Windows x64 stable

Simple time synchronization for engineering PCs. Install AR Fast SNTP, enter a trusted SNTP server IPv4 address, and watch the connection and clock synchronization status in the desktop application.

What's improved

• Clearer, vendor-neutral information across the website, README, historical documentation and status messages.
• A streamlined quick-start guide for Windows and a separate link to the Linux beta.
• A PowerShell helper that verifies the SHA-256 hash of the official Windows installer before opening setup.
• Automated repository terminology checks to keep public copy independent of third-party relay, device or clock-service brands.
• Prior repository maintenance consolidated into this installer: updated desktop UI package versions and clearer GitHub Pages presentation.

Reliability and compatibility

The Windows SNTP protocol and synchronization policy are not changed by this release. Source reply validation, bounded probing, monotonic clock-change protection, persisted server IP settings, automatic network recovery and one service-owned clock correction path remain in place.

The Windows installer keeps the same application identity so existing users can install the new version over an earlier release. The public binary is self-contained; no separate .NET runtime is required.

Install

Download the official ARFastSNTP-Setup-Windows-x64.exe and matching .sha256 from this GitHub release. Run setup, choose the SNTP server IP address, and open AR Fast SNTP from Start.

Platform: Windows x64. The Linux x64 beta is distributed separately.

Testing and scope

The build and regression suite run in GitHub Actions on the exact merged source. The Windows clock is not changed during CI. The original four-PC engineering experience measured rapid correction and network recovery; results can vary with network and time-server conditions.

Use a computer where you have permission to adjust the clock. For publisher signing, extended soak testing and critical infrastructure deployment qualification, see the engineering roadmap.

Source: https://github.com/masarray/arfast-sntp · License: GPL-2.0-or-later.

AR Fast SNTP linux-v0.1.0-beta.1 — experimental Linux x64

Experimental Linux build for authorized engineering and lab testing only. Review README-LINUX.md. Not validated for production SCADA/SOE timing.

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).

AR Fast SNTP v0.10.2 — Windows x64

AR Fast SNTP v0.10.2 — Windows x64

Official public Windows installer, built from the merged multi-source SNTP Windows Studio and network-recovery baseline. One installer executable: ARFastSNTP-Setup-Windows-x64.exe, plus a small .sha256 text checksum file.

Highlights

• Canonical Avalonia Studio with compact NTP Server Explorer, live status, stratum, time offset, server time, RTT with tooltip, subtle zebra rows, and bounded Status History/diagnostics.
• Up to 16 IPv4 unicast NTP sources with live Add/Delete/Enable/Disable without reinstalling or relaunching the Windows Service.
• Single background service with bounded polling and one clock-correction authority.
• All sources OFF: service remains responsive, but no UDP NTP queries or system clock correction; status heartbeat stays alive.
• ON/reconnected network: coalesced NIC events, adapter fingerprint fallback, bounded retry/recovery. Stale samples are discarded before clock selection.
• Clock-epoch and NTP KoD safeguards; post-step verification requires a fresh NTP response.
• Consolidated canonical icon resources for Windows EXEs, Studio, installer, README, and website.

Install or upgrade

Download the installer and checksum under Assets. Compare the checksum in Windows PowerShell:

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

Run installer as administrator on an authorized test/engineering PC. It detects the app's existing service, preserves the saved peer catalog during upgrade, and configures one permanent Windows Service. A new installation asks for a unicast IPv4 NTP server.

The default installer permits Windows clock correction when the source is verified. To run monitor-only on a lab PC, start the installer with /LABSYNC=0. Manage peers afterward from Studio without repeated elevation. Uninstall through Windows Settings → Apps → Installed apps → AR Fast SNTP.

Known limits and release safety

This build is not Authenticode-signed; SmartScreen reputation may be limited. Verify the GitHub release source and checksum. Do not disable antivirus or Group Policy protections merely to install it.

Not certified for operational SCADA, SOE, historian, or GPS-grade reference timing. This release is not evidence of 24-hour soak, installer rollback on every older version, deterministic response SLA across every NIC/topology, or full RFC 5905 clock discipline. The ARSAS same-host Npcap RAW→Windows UDP delivery issue is not claimed resolved.

Source: repository · Release acceptance / future industrial certification · Multi-source architecture.

License: GPL-2.0-or-later; LICENSE and NOTICE are included within the installer.

AR Fast SNTP v0.10.1 Preview 1

AR Fast SNTP v0.10.1 Preview 1

First public testing preview · Windows x64 · unsigned Inno installer

This release packages the Windows CI #49 SUCCESS executable from Git commit ef23e4efa0905334c0a7f58c1b03a6573802ce3f, validated in the original project before it was renamed to masarray/arfast-sntp.

Included

• A compact, branded Avalonia Windows Studio and one permanent Windows Service.
• Up to 16 configured IPv4 NTP servers; Add/Delete/Enable/Disable without reinstalling the service.
• Source health, selected source, stratum, offset, server time, RTT with tooltip and status history.
• Bounded SNTPv4 probing, source election/consensus checks, outlier and failover logic.
• Inno Setup x64 installer and diagnostic export.

Download and verify

Download ARFastSNTP-Setup-Windows-x64.exe and ARFastSNTP-Setup-Windows-x64.exe.sha256 from this release's Assets. In PowerShell, run:

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

Compare the reported hexadecimal SHA-256 digest to the .sha256 file. This is a code-unsigned preview; verification of the publisher identity is not available.

Important safety information

For trusted isolated lab/test PCs only. Not for production SCADA, SOE, historian or any critical system. The default installer activates clock correction when it has an eligible reference. To test monitor-only operation, run the installer with /LABSYNC=0. Administrator approval is required at install time.

Reported real tests accepted two public Cloudflare NTP IPv4 replies and a small clock correction. They do not establish GPS-grade precision, independent sources, robust recovery from a very large time jump, or production acceptance.

Outstanding validation

Windows DPI 100–200% and live GUI behavior; real 1/2/3-source failover and conflicting independent servers; long-running resource soak; upgraded service rollback/uninstall; large clock-step barrier and antivirus/TLS effects. ARSAS/Npcap RAW same-host Mode 4 delivery remains unverified. Track these in Issue #2.

No public stable release claim is made for this version. Feedback, redacted diagnostics and screenshots are welcome.