Rustdesk on Azure not working

Question

Rustdesk on Azure not working

Fred Claus 1

I'm trying to set up rustdesk on Azure. I've followed all the instructions for rustdesk on Docker. I've added the inbound rules that rustdesk wants, I've even troubleshooted them by removing and recreating them a dozen times. When I go to try to connect the client to the server it fails to connect. When I run a port scan, port 22 works fine, but the ports in the inbound rules I created don't. The rule numbers are very low so they are not hit by other rules. I've been playing with this for months now, so before I give up and use a different tool, I wanted to see if anyone could help me figure out what I'm doing wrong.

UFW is not turned on in the vm by the way.

Jilakara Hemalatha 245 Reputation points Microsoft External Staff Moderator

2025-08-13T02:48:04.9333333+00:00
Hi Fred Claus,

To assist you further with the Rustdesk connectivity issue on Azure, could you please provide the following details:

Which Azure VM OS are you using?

Are you running the Rustdesk server directly on the VM or inside a Docker container? and Which Rustdesk server version are you using?

Could you share the exact NSG rules you've configured?

Is the NSG applied at the NIC level, subnet level, or both?

Besides UFW being disabled, are there any other OS-level firewalls active (e.g., iptables, firewalld)?

Is the VM’s public IP directly assigned to the VM’s NIC, or is it behind an Azure Load Balancer? If there is a Load Balancer, have inbound rules/NAT rules been created for the Rustdesk ports?

Are there any specific error messages or logs when the client fails to connect to the server?
Fred Claus 1 Reputation point

2025-08-13T18:27:39.7466667+00:00

I'm using Ubuntu 24.04 as an OS, and I'm running RustDesk on Docker. I set up individual rules to allow TCP on the following ports: 21115, 21116, 21117, 21118, 21119. I also set up one rule to allow UDP on port 21116. The rules were all the default information that is in the inbound rule, but I changed the destination port and the type. I'm not sure if NSG is applied NIC level or the subnet. I didn't make any changes (nor do I know how) to that.

Firewalls, I have none set up in the OS itself, only in the NSG. For the public IP question, I'm going to say NIC. In the properties section, I see my public IP, and it says (Network Interface) next to it. Load balancing has nothing in it. The only error message I get when I try to connect the client to the server is "Not Ready: Please check your connection." When I try to do a port scan on them, port 22 works fine, but the others all say "Connection Refused".

I think that answers all your questions. Please let me know if I missed one.
Jilakara Hemalatha 245 Reputation points Microsoft External Staff Moderator

2025-08-14T13:40:46.24+00:00
Hi Fred Claus,

Could you please verify whether the required ports are actively listening on the VM by running the following command:

sudo ss -tulpn | egrep '2111[5-9]|21116'

If no service is listening on a given port, external clients (such as RustDesk) will not be able to connect, even if your NSG/firewall rules are correctly configured. Ensuring that RustDesk is running and bound to the expected ports inside the VM.

please refer the below screenshot for the port status are listening.

Hope this helps! Please let me know if you have any queries

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Your answer

Jilakara Hemalatha 245 Reputation points Microsoft External Staff Moderator

2025-08-13T02:48:04.9333333+00:00

Hi Fred Claus,

To assist you further with the Rustdesk connectivity issue on Azure, could you please provide the following details:

Which Azure VM OS are you using?

Are you running the Rustdesk server directly on the VM or inside a Docker container? and Which Rustdesk server version are you using?

Could you share the exact NSG rules you've configured?

Is the NSG applied at the NIC level, subnet level, or both?

Besides UFW being disabled, are there any other OS-level firewalls active (e.g., iptables, firewalld)?

Is the VM’s public IP directly assigned to the VM’s NIC, or is it behind an Azure Load Balancer? If there is a Load Balancer, have inbound rules/NAT rules been created for the Rustdesk ports?

Are there any specific error messages or logs when the client fails to connect to the server?
Fred Claus 1 Reputation point

2025-08-13T18:27:39.7466667+00:00

I'm using Ubuntu 24.04 as an OS, and I'm running RustDesk on Docker. I set up individual rules to allow TCP on the following ports: 21115, 21116, 21117, 21118, 21119. I also set up one rule to allow UDP on port 21116. The rules were all the default information that is in the inbound rule, but I changed the destination port and the type. I'm not sure if NSG is applied NIC level or the subnet. I didn't make any changes (nor do I know how) to that.

Firewalls, I have none set up in the OS itself, only in the NSG. For the public IP question, I'm going to say NIC. In the properties section, I see my public IP, and it says (Network Interface) next to it. Load balancing has nothing in it. The only error message I get when I try to connect the client to the server is "Not Ready: Please check your connection." When I try to do a port scan on them, port 22 works fine, but the others all say "Connection Refused".

I think that answers all your questions. Please let me know if I missed one.
Jilakara Hemalatha 245 Reputation points Microsoft External Staff Moderator

2025-08-14T13:40:46.24+00:00

Hi Fred Claus,

Could you please verify whether the required ports are actively listening on the VM by running the following command:

sudo ss -tulpn | egrep '2111[5-9]|21116'

If no service is listening on a given port, external clients (such as RustDesk) will not be able to connect, even if your NSG/firewall rules are correctly configured. Ensuring that RustDesk is running and bound to the expected ports inside the VM.

please refer the below screenshot for the port status are listening.

Hope this helps! Please let me know if you have any queries

Answer 1

Fred Claus 1

sorry I posted in the wrong spot. Moving my comment.

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Rustdesk on Azure not working

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