Log in to the H3C ER3 100 router and select Advanced Settings-Address Translation, as shown in the following figure:

Then click the "Virtual Server" option on the right and click "Add" below, as shown below:

In the pop-up dialog box, in the preset setting options, if you need to map port 2 1, select FTP, and if you want to map port 80, select WEB(http). Here we choose custom, as shown in the figure below:

Write the service name casually. An external port is a port that you want to map to the outside. Here we take the mapping of port 3389 as an example. Similar to the internal port, the internal server IP is the IP address of the internal server, such as192.168.1.5. Select the enable option, as follows:

Click Add to complete the mapping of H3C ER3 100 routing ports. Now try to enter your public IP to connect!

Note: For port mapping, you must open the corresponding port number on the computer where you want to map the port.