porttivälitys

Porttivälitys, often translated as port forwarding, is a networking technique used to direct traffic from one network device to another. It is commonly implemented on routers and firewalls to allow external devices to access services running on internal private networks. When a request arrives at a public IP address and a specific port number, the port forwarding rule tells the router to redirect that request to a particular device's private IP address and port within the local network. This is essential for making services like game servers, web servers, or remote access applications accessible from the internet.

The configuration typically involves specifying the external port, the internal IP address of the target device, and the internal port. For example, a user might configure port forwarding to send traffic arriving at their router's public IP address on port 80 (the standard HTTP port) to a web server located at 192.168.1.100 on port 80. Without port forwarding, external requests to these internal services would be blocked by the router's firewall. While useful, port forwarding can also introduce security risks if not configured carefully, as it exposes internal services to the public internet. It's important to only forward ports for services that are necessary and to ensure those services are properly secured.