If you want to know more about Thunderbolt connections and which devices support it with Duet Display, go to this article.

The Thunderbolt Bridge serves as a network interface, enabling data transfer between two devices using a Thunderbolt cable. This connection should establish automatically when the cable links the devices. To verify the Thunderbolt Bridge setup:

• Connect your primary and secondary computers using the Thunderbolt cable. Insert one end of the cable into the primary device and the other into the secondary device. On each device, navigate to the Apple menu > System Preferences > Network.
• In the left-side panel, you’ll see connection types listed. As you’re using a TB cable, look for 'Thunderbolt Bridge.'
• Once the cable is connected, the connection status in the left-side panel should display a yellow or green dot, labeled as either 'Self-Assigned IP' or 'Connected'.

If the Thunderbolt Bridge shows 'Not Connected' or displays a red dot, it indicates that the devices are not detecting the wired connection. To troubleshoot this issue:

1. Disconnect and reconnect the cable to ensure it’s securely inserted.
2. Try a different Thunderbolt cable, as the current one may have an issue.
3. In the left-side menu, select Thunderbolt Bridge and confirm that Configure IPv4 is set to 'Using DHCP.'
4. Restart both the primary and secondary devices to see if the Bridge connection now appears.

If the issue persists, check out Apple's support article for troubleshooting a Thunderbolt connection on a Mac.

Now, if Duet Display is still not connecting over Thunderbolt, we suggest running a ping test to confirm that the devices can communicate over the cabled connection.

To check if the Thunderbolt Bridge is working outside of Duet Display, open a command line terminal (such as Terminal.app or cmd). Then use the 'ping' command with the Thunderbolt Bridge IP address of the other computer. For example, ping -c 5 10.10.10.1. If you are testing from Mac to Windows, you will need to allow ping through your Windows firewall.

If you see 0% packet loss as shown above, your connection is working correctly. If you see 'Request timeout for icmp_seq' or more than 0% packet loss, double-check the IP address to ensure it was entered correctly. If the IP matches the one you assigned to the other device’s Thunderbolt Bridge then there is an issue with your connection. If ping is not working in either direction there may be an issue with your Thunderbolt cable, or it may not be plugged in correctly.

Other Common Fixes

• If you are not seeing the expected performance increase, try restarting the Duet app on both devices after the above ping test is successful. Duet may be using the internet IP address instead of Thunderbolt. If you suspect that is still the case after restarting Duet, contact support.
• If the Thunderbolt connection is not recognized by the computer, you may need to update your Thunderbolt drivers or firmware. Consult your manufacturer's website for this information. Alternatively, try another Thunderbolt cable and double-check your ports.
• When establishing the Thunderbolt connection for the first time, Mac or Windows may need to reboot to load new drivers or re-initialize the network adapter. Contact support if you are still experiencing issues after rebooting both devices.

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If you have any further questions or require assistance, please contact us at team@duetdisplay.com - we're happy to help!