Set up a web server in the LAN and fix the intranet IP of this machine. Win2003 system is needed, but XP can't, because the number of IIS connections is limited. Put the program on it after it is built, and other computers can directly enter the IP address of this server to access it.

If you want to log on to the external network, you must first map the router of the local area network to this server. Generally, a DMZ host should be set in the router, and then the intranet IP of the server should be filled in.

When accessing the external network, you need to enter the IP of the external network, which can be found on IP 138.

If your broadband is a fixed IP, just apply for a domain name to point to this IP. If it is not a fixed IP, you need to use a dynamic domain name, which is now commonly used as a "peanut shell"