However, the system's own VPN function is very limited, and it is very troublesome to set up, otherwise other brands of VPN will have no living space.

I recommend a VPN for you. It's called Paikes Virtual Private Network. This is a pure software product, and there is no need to replace the existing network equipment. Directly installed on the computer at the headquarters, the setup is simple, and the VPNserver is built. Then the client dials in from the external network. A complete VPN network is built. . Compared with hardware VPN, the management is simple, and there is no need to replace equipment and redesign the topology diagram. The cost is much lower. Maintenance is also very simple