Opening firewall ports

For services that need to be reached from outside — websites (80/443), game servers (e.g., Minecraft 25565), programs you've built yourself (e.g., 8080) — you need to open the matching port in the server's firewall.

⚠️ Before turning on the firewall, allow your access port first (Linux SSH 22, Windows RDP 3389). If you block this port, you won't be able to connect to the server, and your Dashboard may also show "Server not responding". If you blocked it by mistake, you can get in through the browser console (VNC) and undo it.

Linux (Ubuntu) — ufw

Ubuntu comes with a simple firewall tool called ufw.

Check the current status

sudo ufw status

Status: inactive means the firewall is off and every port is open.

Turn on the firewall (first time only)

sudo ufw allow 22/tcp      # Allow SSH first (required!)
sudo ufw enable

Open / close ports

sudo ufw allow 80/tcp          # Web (HTTP)
sudo ufw allow 443/tcp         # Web (HTTPS)
sudo ufw allow 25565/tcp       # Minecraft
sudo ufw delete allow 25565/tcp   # Close a port you opened

Allow only from a specific IP

For ports only you need to reach, like a DB, it's safer to allow them only from your own IP.

sudo ufw allow from my-ip-address to any port 3306 proto tcp

Windows server — Windows Defender Firewall

Set it up on screen

1. Win + R → type wf.msc → Enter
2. Inbound Rules on the left → New Rule on the right
3. Select Port → TCP, and enter the port number in "Specific local ports" (e.g., 8080)
4. Allow the connection → check all the profiles it should apply to → enter a rule name and click Finish

Set it up in one line with PowerShell

Open PowerShell as administrator and enter:

New-NetFirewallRule -DisplayName "My App 8080" -Direction Inbound -Protocol TCP -LocalPort 8080 -Action Allow

I opened the port but still can't connect

• Check that the program is set to listen not on 127.0.0.1 (internal only) but on 0.0.0.0 (all addresses).
• Check that the program is actually running on the server. On Linux, you can see listening ports with sudo ss -tlnp.
• If it still doesn't work, check Can't connect to your server or contact technical support.