How to Troubleshoot Connection Issues

No Comments

Please follow this guide if you are experiencing trouble with connection issues, such as clients failing to connect to LuminosityLink Workstation.


Are you testing on a local PC?

When attempting to connect to a PC on your local network, use your main computers local (Private) IP address as the Backup DNS/IP within Client Builder. Information on how to find your local IP Address can be found here.

Could security software being interfering with the connection?

Security Software, especially Firewalls, can interfere with the connection. Disable your firewall/security software before continuing.

Are you using the port in another application (such as TCPListener)?

Ensure the port you are listening to is not being used in any other application. Do not use tools such as “TCP Listener” to listen to the port. Do not use the same port in multiple applications. You should use a dedicated port for LuminosityLink.

Is a client binary already running on your test machine?

Only one client binary will run on a PC at a time. If you wish to run a new one, you must first remove the old one. Use the LuminosityLink Removal Tool to uninstall previous client binaries.

Are you testing on a virtual machine?

If testing on a virtual machine: networking can be complicated. It is recommended to use bridged network adapter in your machines networking setting. Afterwards, follow the first tip, and use your computers local IP address as the Backup DNS/IP before testing.

Almost all connection issues unrelated to DNS and Port can be resolved by following the above. If these do not apply to you, please test your DNS and Port using this guide.


Testing Your DNS

A DNS, also known as “Domain Name System” is a hostname which resolves to your ip address. Did you know ‘’ is a DNS? It resolves to the IP address of which Google is hosted on.

Why use a DNS? Simple – in case your IP changes, your client(s) will know what IP to connect to.

Testing your DNS in Luminosity is extremely easy. Under the Client Builder, Insert your DNS and hit “Test DNS”. Luminosity will see if your DNS resolves to your IP.

After hitting “Test DNS”, you will given one of these three results:

Your DNS is valid and resolves to your IP
Simply put – your DNS works fine, and it resolves to your IP.

Your DNS is valid, but does not resolve to your IP
Your DNS does not resolve to your IP. Sometimes, DNS takes time to update. Please ensure your DNS is updated to your IP.

Unable to test DNS. You probably typed in an invalid DNS, or your internet is offline.
The hostname you input does not exist, or it cannot be resolved. This means the DNS is invalid. If you just created this DNS, please be patient – it may take up to 12 hours to resolve properly!

Testing Your Port Forwarding

Before following this part of the troubleshooting guide, ensure that you have a port forwarded and ready to test. This is a troubleshooting guide – not a setup guide.

To start, go to “Settings” and select “Ports”

IMPORTANT NOTICE: “Total Incoming Connections” DOES NOT count the amount of clients you have online. It counts the amount of total connections incoming. When you test your port, it goes up. If a client reconnects, it goes up.

Add your Port, right click hit and hit “Test Port”. You will be given one of these three responses:

The Port is open and working, and “Total Incoming Connections” goes up!
Everything is setup properly and Luminosity is accepting connections. You have nothing to worry about.

LuminosityLink says success, but “Total Incoming Connections” doesn’t go up!
This means that another application, instead of Luminosity, is accepting the connection. Usually another RAT. Try closing all applications and ensuring Luminosity has a port dedicated to itself.

Your LuminosityLink clients will not connect, because something else is using this port!

Luminosity says the Port is Closed
Either your port is not forwarded properly (most likely case), or Luminosity is failing to accept the connection due to a firewall. If you are using a VPN to port forward, please contact your VPN Provider for support. If you are using your modem/router to port forward, please read the instructions and google the model number for proper settings.

There is a possibility the built-in port test is wrong. You may test your port on in this case.

For further assistance, feel free to submit a ticket, or send an email.

Official LuminosityLink Blog

Get the latest news, updates, and tutorials on how to get the most out of LuminosityLink.

Need Assistance?

Support is provided free to all customers. You may email us for pre-sale questions, support, and licensing inquiries.

Subscribe to our newsletter!

Fields marked with an * are required

More from our blog

See all posts
No Comments

Recent Posts


Leave a Comment