One: Use VPN router to build server (VPN type: IPSEC or L2TP)

The VPN server is built on the VPN router above the central computer, and the computer under the 4G / 5G VPN industrial router and the computer under the VPN router of the Lulu 4G / 5G VPN industrial router are interconnected by binding the subnets of the two parties to realize data communication. The server’s network must have a fixed public IP or a fixed domain name (an address that can be found on the Internet).Two: use Alibaba Cloud server to build a VPN server (VPN type: PPTP or L2TP)

Purchase a server 2008 cloud server from Alibaba Cloud, and use this server2008 system to build a VPN server. This server has a public IP and can be directly connected. Usually just open the webpage on any computer connected to the Internet and log in to the Alibaba Cloud server to operate.

Example: VPN server is TL-ER6520 tplink enterprise router, VPN client is Alocter AD7028-A industrial grade 4G / 5G full Netcom dual card dual-mode industrial router (for the first networking method).

Step 1: Add VPN tunnel address pool;

Step 2: Configure the L2TP interface and parameters;

Step 3: Add VPN user information, each user is assigned a network segment, for example, test1 (same password) is network segment 1, test2 is network segment 2.

Two user names have been added.

Step 4: If it is an APN dedicated network card, the online monitoring server needs to fill in a long-term fixed and valid IP address in the dedicated network. If it is not available, the online function can be turned off. If it is an ordinary traffic network card, skip this step.

Step 5: Configure L2TP client parameters, especially the remote subnet must be the subnet of the remote server;

Step 5: Configure L2TP client parameters, especially the remote subnet must be the subnet of the remote server;

Then check the VPN server tunnel connection status, it shows that there is a client connection success;

Step 6: The two subnets ping each other to prove that the two-terminal network has been successfully opened, and the corresponding network operation can be performed;