(Win2003 uses dual network card routing to terminate the access table and internal network. Generally, this situation occurs in the enterprise, which meets some special requirements of some special groups (such as network administrators and CEOs). In order to be safe, the internal network of the enterprise generally shields the download and chat software, etc. You can use dual network cards, one for the internal network and the other for the external network, to terminate the Internet access and other operations through the external network line, and the internal use of the internal network line. Preliminary information: dual network card, win2003 main)