Intranet users often need to contact and distinguish between external ports and internal ports when setting port mapping, but what is the external port? What is an internal port? This article will explain in detail the definition and difference between external port and internal port, and how to set up port mapping.

The internal port in the virtual server settings (port mapping) refers to the port used by the internal server application, and the external port refers to the port used by the external network access mapping server application.

For example, a web server is set in the intranet, and the default port is 80 (you can also change the default port to something else). This 80 is the internal port. If you use the default port 80 for external network access, you can fill in 80 (port mapping) at the beginning and end of the external port column of the virtual server. If you want to use port 8888 to access (in some areas, operators will block port 80, so you need to change the external port settings), then fill in 8888 in the column of external port. Web access needs to be added after the address to be accessed: 8888.

The external network port is the port for Internet users to access the server. When accessing data to the WAN port, the router will replace the external port of the access request data with the internal port, and then forward it to the internal server, so that the server can receive access normally. The main purpose of external ports is to reduce the scanning attacks of external networks on public ports and operator restrictions.