Port Scanner
Scan open ports on your IP address – check which services are accessible from the outside.
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How the Port Scanner Works
Our port scanner checks your current public IP address for commonly used and security-critical ports. TCP connection attempts are made to selected ports and the status (open, closed or filtered) is reported back. The test helps you identify unnecessarily exposed services on your network.
Frequently Asked Questions about Port Scanner
What are ports and why are they important?
Ports are virtual endpoints for network communication. Each service uses a specific port: e.g. port 80 for HTTP, port 443 for HTTPS, port 22 for SSH. Open ports can be a security risk if unnecessary services are accessible from outside.
Is port scanning legal?
Scanning your own IP address or systems you have permission for is legal. Unauthorised scanning of other systems may be considered preparation for an attack depending on the country. Only use this tool on your own systems or with explicit permission.
What should I do if unexpected ports are open?
Identify the service using the port and check if it is needed. Unnecessary services should be disabled or blocked by firewall. Particularly critical are ports like 21 (FTP), 23 (Telnet) and 3389 (RDP), which are frequent targets of attacks.