I keep having problems connecting through NVIDIA Sync to my DGX Spark

[druizsilva]

Hi,

I keep having problems connecting to my DGX Spark founders edition with NVIDIA Sync using my MacBook Pro 16 inches 2019 with the latest version of Sequoia.

Initially I had problems connecting with my Spark but I was able to connect at least tree times (I raised a ticket into this forum but I connected later so I didn’t follow), however sessions only lasted while my MacBook Pro session until shutdown. I installed Cursor, AI Workbench, Open WebUI and ComfUI during those connections.

However after the lap shutdown, when restarting my lap with the already created NVIDIA Sync session, it appears me the following error :

I did a lot of things, like deleting the known_host file in the path /Users/darusi/.ssh (8 times) , also the config file like this:

Also I deleted the configuration into the NVIDIA Sync directory as follows:

I reinstalled NVIDIA Sync lots of times (10 or more) but no connection happened.

Reviewing the log file, it appears like there is no route to host, however we are on the same network with no device between like a FW or router as follows:

“level”:“error”,“pid”:4228,“error”:“dial tcp 192.168.68.111:22: connect: no route to host”,“addresses”:[“192.168.68.111”],“time”:“2025-12-28T22:06:08-06:00”,“message”:“Could not dial any address for 192.168.68.111:22”}
{“level”:“error”,“pid”:4228,“error”:“dial tcp 192.168.68.111:22: connect: no route to host”,“time”:“2025-12-28T22:06:08-06:00”,“message”:“Could not dial 192.168.68.111:22”}
{“level”:“warn”,“pid”:4228,“error”:“dial tcp 192.168.68.111:22: connect: no route to host”,“time”:“2025-12-28T22:06:08-06:00”,“message”:“could not get remote environment variables”}

I can access the DGX spark through ssh with no issues, I’ve been able to start certain dockers processes like Open WebIUI and Cursor, but not Nvidia AI Workbench, that presents the very same error:

So is consistent with the NVIDIA Sync error. I’m attaching the logs with the evidence for your analysis since I want to restore my NVIDIA Sync connection:

nvsync.log (18.7 KB)

NVIDIA Sync-desktop.log (730.3 KB)

Any comment or support please let me know

Thanks in advance

[griffith.mark]

I had the same problem. If you setup NVIDIA sync using IP address you can get this problem.
SSH to host works using IP address works, but NVIDIA Sync refuses to work.

Solution: Setup SSH manually using Host rather than IP and I expect that this will fix the problem with NVIDIA Sync.

[druizsilva]

thank you Marc. I will try it and I will let you know the result. Thank you for being so kind assisting me.

[druizsilva]

Dear Mark,

I followed your suggestions, I modified either the known_host file in to the MacBook Pro, replacing the IP address with the hostname. After that, I applied the MacOS Sequoia update 15.7.3 in order to have the latest OS in case of need. I’ve waited for the restart, and tried again to connect through Nvidia Sync using the parameters hostname instead of the IP address with the extension hostname.local. And now it worked connecting immediately.

Thanks for your kind support. Anyway I will check if like on other occasions, on the next lap restart I may be able to connect again. If not, I will raise a new ticket into this forum.

Thanks again for your help.

Best Regards

David Ruiz