Detailed analysis of the VPN protocol of industrial 4G routers

Detailed analysis of the VPN protocol of industrial 4G routers

The function of a VPN virtual private network is to establish a private network on a public network and perform encrypted communication, which is widely used in corporate networks.

4G industrial routers basically have VPN functions. Common VPN functions are divided into Client and Server. In terms of protocol, they are divided into PPTP, L2TP, ipsec, openvpn, gre, sstp, etc.

The common VPN functions in 4G industrial routers are divided into Client and Server, and are divided into PPTP, L2TP, ipsec, openvpn, gre, sstp, etc.

1. PPTP Client

PPTP is a point-to-point tunneling protocol. It uses a TCP (port 1723) connection to maintain the tunnel, and uses the general routing encapsulation (GRE) technology to encapsulate data into PPP data frames for transmission through the tunnel, and encapsulate the load in the PPP frame The data is encrypted or compressed. Among them, MPPE will encrypt the PPP frame with the encryption key generated by the MS-CHAP, MS-CHAP V2 or EAP-TLS authentication process.

PPTP site-to-site setting method: For example, a company's head office is located in Jinan, and the branch is in Shenzhen. Now it is necessary to set up a network so that all employees in Shenzhen can safely access the internal network of the head office.

Assume that the PPTP server of the head office has been set up (due to the different configuration methods of different servers, you can refer to the configuration instructions of the server).

2. L2TP Client

L2TP is a layer two tunneling protocol, similar to PPTP. At present, G808 supports multiple authentication methods such as tunnel password authentication and CHAP. The encryption supports the pre-shared key of MPPE and L2TP OVER IPSEC, and the client static IP can be set. Specific configuration instructions: In the advanced settings, you can select the corresponding authentication and encryption methods in the identity authentication

3. IPSEC configuration

The IPSEC protocol is not a separate protocol. It provides a complete set of architectures for network data security on the application and IP layer, including network authentication protocols AH, ESP, IKE, and some algorithms for network authentication and encryption.

The AH protocol and ESP protocol are used to provide security.

4. OPENVPN Client

OPENVPN is an application layer VPN implementation based on the Openssl library. It supports certificate-based two-way authentication, which means that the client needs to authenticate the server, and the server must also authenticate the client.

5. GRE

The GRE (Generic Routing Encapsulation, Generic Routing Encapsulation) protocol encapsulates the datagrams of certain network layer protocols (such as IP and IPX) so that these encapsulated datagrams can be transmitted in another network layer protocol (such as IP) . GRE uses Tunnel (tunnel) technology, which is the third layer tunneling protocol of VPN (Virtual Private Network).

6. SSTP Client

SSTP, also known as Secure Socket Tunneling Protocol, is a protocol applied to the Internet. It can create a VPN tunnel transmitted over HTTPS. SSTP is only suitable for remote access and cannot support VPN tunnels between sites.

Industrial VPN router application

At present, 4G industrial routers are mainly used in the Internet of Things industry, such as electric power, water conservancy, transportation, finance, agriculture, forestry, coal mining, petrochemical, environmental monitoring and protection, meteorology, fire protection, public safety, smart home, automation and other fields.

The above is the detailed analysis of the industrial-grade 4G router VPN protocol.