# NVIDIA Sync 0.64.24 marks direct LAN DGX Spark disconnected while nvsync tunnel remains RUNNING **URL:** \ **Category:** DGX Spark / GB10\ **Created:** [May 26, 2026, 4:02pm UTC](https://forums.developer.nvidia.com/t/nvidia-sync-0-64-24-marks-direct-lan-dgx-spark-disconnected-while-nvsync-tunnel-remains-running/371367 "2026-05-26T16:02:52Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![bradxmarshall](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@bradxmarshall](https://forums.developer.nvidia.com/u/bradxmarshall)\ **Post date:** [May 26, 2026, 4:02pm UTC](https://forums.developer.nvidia.com/t/nvidia-sync-0-64-24-marks-direct-lan-dgx-spark-disconnected-while-nvsync-tunnel-remains-running/371367/1 "2026-05-26T16:02:52Z")
# NVIDIA Sync Escalation Report ## Suggested Forum / Support Title NVIDIA Sync 0.64.24 marks direct LAN DGX Spark disconnected while nvsync tunnel remains RUNNING ## Summary NVIDIA Sync 0.64.24 on Windows repeatedly marks a DGX Spark direct LAN connection as disconnected after roughly 45-70 seconds, even though the underlying `nvsync-amd64.exe` tunnel process remains running and its local forwarded ports remain reachable. This was reproduced after a clean NVIDIA Sync profile reset, with no Tailscale device, no `.local` hosts-file workaround, and a direct LAN device added by IP address. ## Environment - Client: Windows 11 Pro laptop `NEELTJE` - NVIDIA Sync: 0.64.24 - DGX Spark hostname: `spark-fab4` - DGX Spark LAN IP: `192.168.20.10` - Laptop LAN IP observed by Spark: `192.168.40.117` - Connection type tested: Direct LAN SSH - Tailscale integration: disabled / not used for the clean reproduction - Device entry used for clean reproduction: - Name: `spark-fab4` - Hostname/IP: `192.168.20.10` - User: `brad` - Port: `22` ## Expected Behavior Per NVIDIA Sync documentation, after adding and connecting a device, Sync should remain connected and allow custom applications to stay bound until stopped or disconnected. Opening another custom app should not cause the device to reconnect and tear down existing app tunnels. ## Actual Behavior 1. NVIDIA Sync connects to `192.168.20.10`. 2. The desktop log shows Sync calling: - `connect 192.168.20.10 --detach` - `open 192.168.20.10 11000` 3. `nvsync-amd64.exe status 192.168.20.10` reports `RUNNING`. 4. Local ports remain reachable: - `127.0.0.1:11000` - `127.0.0.1:11002` 5. After about 45-70 seconds, NVIDIA Sync desktop state flips the device back to `disconnected`. 6. Clicking the tray icon often shows Connect again. 7. Reconnecting or opening another custom app can tear down previously opened custom app tunnels. DGX Dashboard often survives. ## Key Evidence `nvsync.log` shows the tunnel starts: hostname=“192.168.20.10” message=“Dialing remote machine” duration=“45s” message=“Starting keepalive goroutine” port=11002 message=“Port tunnel opened and ready” port=11000 message=“Port tunnel opened and ready” Then the health/status path fails: error=“ssh: rejected: connect failed (Connection refused)” message=“Could not dial localhost:11002” At the same time, CLI status still reports the tunnel as running: { “status”: “RUNNING”, “error”: “”, “dashboard\_installed”: true, “tailscale”: { “enrolled”: false }, “ports”: { “11000”: { “status”: “OPENED”, “error”: “” }, “11002”: { “status”: “OPENED”, “error”: “” } } } But `state-store.json` is updated to: device status: disconnected hostname: 192.168.20.10 tailscaleEnrolled: false dashboardInstalled: true ## Spark-Side Checks Spark services are stable and listening: 127.0.0.1:11000 DGX Dashboard 0.0.0.0:12000 Open WebUI 127.0.0.1:12001 Spark LLM Control 0.0.0.0:12002 Spark Files 0.0.0.0:13001 Spark LLM Ops Spark does not appear to have a listener on remote `localhost:11002`, which seems to be the path NVIDIA Sync uses for connection health/status. That refusal appears to cause the desktop app to mark the device disconnected even though the local tunnel remains running. ## Steps Already Tried - Reset NVIDIA Sync profile completely. - Reinstalled/repaired NVIDIA Sync 0.64.24 from cached installer. - Removed stale FQDN/Tailscale device entries. - Removed `spark-fab4.local` hosts-file workaround. - Added device fresh using direct LAN IP `192.168.20.10`. - Confirmed LAN SSH works independently. - Confirmed `192.168.20.10:22` is reachable from Windows. - Confirmed Tailscale is not part of the clean reproduction. - Confirmed `nvsync-amd64.exe status 192.168.20.10` reports `RUNNING` while desktop state says disconnected. ## Diagnostic Bundle Local diagnostic zip: C:\Users\BradleyMarshall\AppData\Local\Temp\nvidia-sync-reconnect-bug-20260525-161226.zip The bundle contains: - NVIDIA Sync logs - NVIDIA Sync config snapshot - Process command lines - CLI status output - Relevant hosts-file lines ## Request Please advise whether this is a known NVIDIA Sync 0.64.24 issue with the `localhost:11002` health/status path, or whether a Spark-side Sync/Workbench service is expected to be listening on remote `11002`. The main question: Why does NVIDIA Sync desktop mark a direct LAN device disconnected when `nvsync-amd64.exe status` still reports the tunnel as `RUNNING` and local forwarded ports remain reachable? [nvidia-sync-reconnect-bug-20260525-161226.zip](https://forums.developer.nvidia.com/secure-uploads/nvidia/original/4X/b/9/4/b945f5752cc6cb7be259e9d963fc72c8c0ea2c60.zip) (24.0 KB)