dgx-spark-playbooks/nvidia/connect-to-your-spark/README.md

Connect to Your Spark

Use NVIDIA Sync or manual SSH to connect to your Spark

Table of Contents

• Overview
• Connect with NVIDIA Sync
• Connect with Manual SSH

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Overview

Basic idea

If you primarily work on another system, such as a laptop, and want to use your DGX Spark as a remote resource, this playbook shows you how to connect and work over SSH. With SSH, you can securely open a terminal session or tunnel ports to access web apps and APIs on your DGX Spark from your local machine.

There are two approaches: NVIDIA Sync (recommended) for streamlined device management, or manual SSH for direct command-line control.

Before you get started, there are some important concepts to understand:

Secure Shell (SSH) is a cryptographic protocol for securely connecting to a remote computer over an untrusted network. It lets you open a terminal on your DGX Spark as if you were sitting at it, run commands, transfer files, and manage services—all encrypted end-to-end.

SSH tunneling (also called port forwarding) securely maps a port on your laptop (for example, localhost:8888) to a port on the DGX Spark where an app is listening (such as JupyterLab on port 8888). Your browser connects to localhost, and SSH forwards the traffic through the encrypted connection to the remote service without exposing that port on the wider network.

mDNS (Multicast DNS) lets devices discover each other by name on a local network without needing a central DNS server. Your DGX Spark advertises its hostname via mDNS, so you can connect using a name like spark-abcd.local (note the .local suffix), rather than looking up its IP address.

What you'll accomplish

You will establish secure SSH access to your DGX Spark device using either NVIDIA Sync or manual SSH configuration. NVIDIA Sync provides a graphical interface for device management with integrated app launching, while manual SSH gives you direct command-line control with port forwarding capabilities. Both approaches enable you to run terminal commands, access web applications, and manage your DGX Spark remotely from your laptop.

What to know before starting

• Basic terminal/command line usage
• Understanding of SSH concepts and key-based authentication
• Familiarity with network concepts like hostnames, IP addresses, and port forwarding

Prerequisites

• DGX Spark device is set up and you have created a local user account
• Your laptop and DGX Spark are on the same network
• You have your DGX Spark username and password
• You have your device's mDNS hostname (printed on quick start guide) or IP address

Time & risk

Time estimate: 5-10 minutes

Risk level: Low - SSH setup involves credential configuration but no system-level changes to the DGX Spark device

Rollback: SSH key removal can be done by editing ~/.ssh/authorized_keys on the DGX Spark

Connect with NVIDIA Sync

Step 1. Install NVIDIA Sync

Download and install NVIDIA Sync for your operating system. NVIDIA Sync provides a unified interface for managing SSH connections and launching development tools on your DGX Spark device.

::spark-download

For macOS

• After download, open nvidia-sync.dmg
• Drag and drop the app into your Applications folder
• Open NVIDIA Sync from the Applications folder

For Windows

• After download, run the installer .exe
• NVIDIA Sync will automatically start after installation completes

For Debian/Ubuntu

• Configure the package repository:

  curl -fsSL  https://workbench.download.nvidia.com/stable/linux/gpgkey  |  sudo tee -a /etc/apt/trusted.gpg.d/ai-workbench-desktop-key.asc
  echo "deb https://workbench.download.nvidia.com/stable/linux/debian default proprietary" | sudo tee -a /etc/apt/sources.list
  

• Update package lists

  sudo apt update
  

• Install NVIDIA Sync

  sudo apt install nvidia-sync
  

Step 2. Configure Apps

After starting NVIDIA Sync and agreeing to the EULA, select which development tools you want to use. These are tools installed on your laptop that Sync can configure and launch connected to your Spark.

You can modify these selections later in the Settings window. Applications marked "unavailable" require installation on your laptop.

Default Options:

• DGX Dashboard: Web application pre-installed on DGX Spark for system management and integrated JupyterLab access
• Terminal: Your system's built-in terminal with automatic SSH connection

Optional apps (require separate installation):

• VS Code: Download from https://code.visualstudio.com/download
• Cursor: Download from https://cursor.com/downloads
• NVIDIA AI Workbench: Download from https://nvidia.com/workbench

Step 3. Add your DGX Spark device

Finally, connect your DGX Spark by filling out the form:

• Name: A descriptive name (e.g., "My DGX Spark")
• Hostname or IP: The mDNS hostname from your quick start guide (e.g. spark-abcd.local) or an IP address
• Username: Your DGX Spark user account name
• Password: Your DGX Spark user account password

Note: Your password is used only during this initial setup to configure SSH key-based authentication. It is not stored or transmitted after setup completion. NVIDIA Sync will SSH into your device and configure its locally provisioned SSH key pair.

Click add "Add" and NVIDIA Sync will automatically:

1. Generate an SSH key pair on your laptop
2. Connect to your DGX Spark using your provided username and password
3. Add the public key to ~/.ssh/authorized_keys on your device
4. Create an SSH alias locally for future connections
5. Discard your username and password information

Wait for update: After completing system setup for the first time, your device may take several minutes to update and become available on the network. If NVIDIA Sync fails to connect, please wait 3-4 minutes and try again.

Step 4. Access your DGX Spark

Once connected, NVIDIA Sync appears as a system tray/taskbar application. Click the NVIDIA Sync icon to open the device management interface.

Clicking on the large "Connect" and "Disconnect" buttons controls the overall SSH connection to your device.

Set working directory (optional): Choose a default directory that Apps will open in when launched through NVIDIA Sync. This defaults to your home directory on the remote device.

Launch applications: Click on any configured app to open it with automatic SSH connection to your DGX Spark.

"Custom Ports" are configured on the Settings screen to provide access to custom web apps or APIs running on your device.

Step 5. Validate SSH setup

Verify your local SSH configuration is correct by using the SSH alias:

Test direct SSH connection (should not prompt for password)

## Configured if you use mDNS hostname
ssh <SPARK_HOSTNAME>.local

or

## Configured if you use IP address
ssh <IP>

On the DGX Spark, verify you're connected

hostname
whoami

Exit the SSH session

exit

Step 6. Troubleshooting

Symptom	Cause	Fix
Device name doesn't resolve	mDNS blocked on network	Use IP address instead of hostname.local
Connection refused/timeout	DGX Spark not booted or SSH not ready	Wait for device boot completion; SSH available after updates finish
Authentication failed	SSH key setup incomplete	Re-run device setup in NVIDIA Sync; check credentials

Step 7. Next steps

Test your setup by launching a development tool:

• Click the NVIDIA Sync system tray icon.
• Select "Terminal" to open a terminal session on your DGX Spark.
• Or click "DGX Dashboard" to access the web interface at the forwarded localhost port.

Connect with Manual SSH

Step 1. Verify SSH client availability

Confirm that you have an SSH client installed on your system. Most modern operating systems include SSH by default. Run the following in your terminal:

## Check SSH client version
ssh -V

Expected output should show OpenSSH version information.

Step 2. Gather connection information

Collect the required connection details for your DGX Spark:

• Username: Your DGX Spark user account name
• Password: Your DGX Spark account password
• Hostname: Your device's mDNS hostname (from quick start guide, e.g., spark-abcd.local)
• IP Address: Alternative only needed if mDNS doesn't work on your network as described below

In some network configurations, like complex corporate environments, mDNS won't work as expected and you'll have to use your device's IP address directly to connect. You know you are in this situation when you try to SSH and the command hangs indefinitely or you get an error like:

ssh: Could not resolve hostname spark-abcd.local: Name or service not known

Testing mDNS Resolution

To test if mDNS is working, use the ping utility.

ping spark-abcd.local

If mDNS is working and you can SSH using the hostname, you should see something like this:

$ ping -c 3 spark-abcd.local
PING spark-abcd.local (10.9.1.9): 56 data bytes
64 bytes from 10.9.1.9: icmp_seq=0 ttl=64 time=6.902 ms
64 bytes from 10.9.1.9: icmp_seq=1 ttl=64 time=116.335 ms
64 bytes from 10.9.1.9: icmp_seq=2 ttl=64 time=33.301 ms

If mDNS is not working and you will have to use your IP directly, you should see something like this:

$ ping -c 3 spark-abcd.local
ping: cannot resolve spark-abcd.local: Unknown host

If none of these work, you'll need to:

• Log into your router's admin panel to find the IP Address
• Connect a display, keyboard, and mouse to check from the Ubuntu desktop

Step 3. Test initial connection

Connect to your DGX Spark for the first time to verify basic connectivity:

## Connect using mDNS hostname (preferred)
ssh <YOUR_USERNAME>@<SPARK_HOSTNAME>.local

## Alternative: Connect using IP address
ssh <YOUR_USERNAME>@<DEVICE_IP_ADDRESS>

Replace placeholders with your actual values:

• <YOUR_USERNAME>: Your DGX Spark account name
• <SPARK_HOSTNAME>: Device hostname without .local suffix
• <DEVICE_IP_ADDRESS>: Your device's IP address

On first connection, you'll see a host fingerprint warning. Type yes and press Enter, then enter your password when prompted.

Step 4. Verify remote connection

Once connected, confirm you're on the DGX Spark device:

## Check hostname
hostname
## Check system information
uname -a
## Exit the session
exit

Step 5. Use SSH tunneling for web applications

To access web applications running on your DGX Spark, use SSH port forwarding. In this example we'll access the DGX Dashboard web application.

DGX Dashboard runs on localhost, port 11000.

Open the tunnel:

## local port 11000 → remote port 11000
ssh -L 11000:localhost:11000 <YOUR_USERNAME>@<SPARK_HOSTNAME>.local

After establishing the tunnel, access the forwarded web app in your browser: http://localhost:11000

Step 6. Troubleshooting

Symptom	Cause	Fix
ssh: Could not resolve hostname	mDNS not working	Use IP address instead of .local hostname
Connection refused	Device not booted or SSH disabled	Wait for full boot; SSH available after system updates complete
Port forwarding fails	Service not running or port conflict	Verify remote service is active; try different local port

Step 7. Next steps

With SSH access configured, you can:

• Open persistent terminal sessions: ssh <YOUR_USERNAME>@<SPARK_HOSTNAME>.local.
• Forward web application ports: ssh -L <local_port>:localhost:<remote_port> <YOUR_USERNAME>@<SPARK_HOSTNAME>.local.