Jetson Nano Orin, stuck with SSH

Issue Overview

Users are experiencing difficulties connecting to the Nvidia Jetson Nano Orin via SSH from a MacBook. The primary symptom is a warning message indicating that the remote host identification has changed, suggesting a potential security risk such as a man-in-the-middle attack. This issue arises after the user successfully boots the board and logs in locally using a monitor, keyboard, and mouse. Despite the board being connected to WiFi and appearing operational, attempts to connect via SSH result in an error that states:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

The specific context for this issue occurs when the user attempts to SSH into the device using the command ssh [email protected], where "navid" is the username on the Jetson device. The error message references the known_hosts file on the user’s MacBook, indicating that there is an offending ECDSA key.

This problem is consistent across multiple attempts and impacts user experience by preventing remote access to the Jetson device, which is essential for development and testing purposes.

Possible Causes

• Host Key Change: The warning indicates that the host key has changed, which can happen if the system was re-flashed or if there was a significant change in configuration.
• Reinstallation or Flashing: If the Jetson device was recently flashed with a new image, it may generate a new SSH host key, leading to this warning.
• DNS Resolution Issues: If there are changes in how the device is identified on the network (e.g., using a different IP address), this can trigger host key verification failures.
• User Configuration Errors: If there are discrepancies between usernames or configurations on different devices (e.g., using different usernames for SSH connections), it can lead to confusion and connection issues.
• Environmental Factors: Network instability or incorrect network settings could also contribute to connectivity issues.

Troubleshooting Steps, Solutions & Fixes

1. Remove Offending Key:

   • Execute the following command on your MacBook to remove the offending key from the known_hosts file:

     ssh-keygen -f /Users/navidkhajouei/.ssh/known_hosts -R 192.168.55.1
     

   • This command removes any stored keys associated with the specified IP address, allowing you to connect without encountering the warning.

2. Verify SSH Configuration:

   • Ensure that SSH is enabled on your Jetson Nano by running:

     sudo systemctl enable ssh
     

   • Check if you can access SSH services locally on the Jetson device.

3. Connect Using Correct Username:

   • Ensure you are using the correct username when attempting to connect via SSH. The command should reflect your Jetson Nano username:

     ssh <your_username>@192.168.55.1
     

   • Replace <your_username> with your actual username on the Jetson device.

4. Check Network Connection:

   • Confirm that both devices (MacBook and Jetson) are connected to the same network.
   • Use ifconfig on your Jetson device to verify its IP address.

5. Reboot Devices:

   • Sometimes rebooting both your MacBook and Jetson device can resolve transient connectivity issues.

6. Documentation and Resources:

   • Refer to Nvidia’s official documentation for further guidance on setting up SSH connections with Jetson devices.
   • Consider checking community forums for additional troubleshooting tips and shared experiences from other users facing similar issues.

7. Best Practices:

   • Always back up your known_hosts file before making changes.
   • Regularly update your system and firmware to avoid compatibility issues.
   • If you frequently change configurations or reflash your device, consider maintaining a separate known_hosts file for different setups.

8. Unresolved Aspects:

   • Users may still experience issues if they continue receiving warnings after following these steps; further investigation into network settings or potential hardware issues may be necessary.

By following these troubleshooting steps, users should be able to resolve their SSH connectivity issues with the Nvidia Jetson Nano Orin effectively.