How do I check if port 27015 is open?

Enter your public IP or hostname into the scanner tool and click Check. A sub-second raw TCP socket handshake will be initiated from our edge server to port 27015 on your target. If the 3-way handshake finishes with SYN-ACK, the port is OPEN. If an RST packet is returned, the host is reachable but the port is CLOSED. If packets time out without response, the port is FILTERED by an ISP or firewall.

Is port 27015 safe to expose to the public internet?

Port 27015 is generally safe to expose when running standard, patched services with strong authentication. However, always ensure your software is updated and access control policies are strictly enforced.

Why does port 27015 show as closed or filtered?

If port 27015 reports CLOSED or FILTERED, confirm that: 1) Your service is actively running and bound to 0.0.0.0 (not just localhost/127.0.0.1); 2) Your router has a port forwarding rule directing external port 27015 to your machine's local IP; 3) Your operating system firewall (Windows Defender Firewall, ufw, or iptables) allows incoming connections on port 27015.

PORT 27015 TCP/UDP Gaming Low Risk

Port 27015 (Steam Dedicated Server / CS2) Open Check

Q: What is port 27015 used for?

Port 27015 is the standard TCP/UDP port used for Steam Dedicated Server / CS2. It is commonly used by Counter-Strike 2, Team Fortress 2, Garry's Mod, Left 4 Dead 2, ARK: Survival Evolved. Default port for Valve Source Engine multiplayer dedicated game servers including Counter-Strike 2, TF2, and Garry's Mod.