What is port 2456 used for?

Port 2456 is the standard TCP/UDP port used for Valheim Dedicated Server. It is commonly used by valheim_server.exe, Valheim Docker. Default connection port for Iron Gate Valheim dedicated multiplayer servers.

How do I check if port 2456 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 2456 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 2456 safe to expose to the public internet?

Port 2456 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 2456 show as closed or filtered?

If port 2456 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 2456 to your machine's local IP; 3) Your operating system firewall (Windows Defender Firewall, ufw, or iptables) allows incoming connections on port 2456.