VPN
Virtual Private Network (VPN) refers to the technology for establishing a private network on a public network. It is called virtual network, mainly because the connection between any two nodes of the VPN network does not have the end-to-end physical link required by the traditional private network, but is built on the network platform provided by the public network service provider, for example, user data is transmitted in a logical network over the Internet, ATM (asynchronous transmission mode>, and framerelay (Frame Relay. It covers extensions of private networks that encapsulate, encrypt, and authenticate links across shared networks or public networks.
Advantages of VPC
(1) UseVPNLow Cost Reduction-built through public networksVPNTo save a lot of communication costs, without the need to invest a lot of manpower and material resources to install and maintainWan(WAN) devices and remote access devices.
(2) secure and reliable transmission data-VPC products use encryption, identity verification, and other security technologies to ensure the reliability of connected users and the security and confidentiality of data transmission.
(3) convenient and flexible connection-if a user wants to connect to a partner without a virtual private network, the Information Technology Department of both parties must negotiate on how to establish a lease line or frame relay line between the two parties, with the virtual private network, you only need to configure the Security connection information for both parties.
(4) full control-the virtual private network can be used by usersISPAnd have full control over your network. You can only use the network resources provided by the ISP. You can manage other security settings and network management changes on your own. You can also create a virtual private network on your own within the enterprise.
Features
(1) security assurance
VPNEstablish a tunnel and use encryption technology to encrypt the transmitted data to ensure data privacy and security.
(2) Service Quality Assurance
VPNIt can provide different levels of service quality assurance for different users.
(3) scalability and flexibility
VPNSupportedInterneT andExtraneT.
(4) manageability
VPNIt can be conveniently managed by users and carriers.
By VPN Application category:
1)Access VPN(Remote Access VPN): data traffic from the client to the gateway that uses the public network as the backbone network to transmit the VPN between devices;
2)Intranet VPN(Intranet VPN): Gateway-to-gateway connects resources from the same company through the company's network architecture;
3)Exclusive VPN(External Network VPN): with the partner's Enterprise NetworkExistsConnects a company to resources of another company;
By VPN Protocol
VPNThere are three main tunnel protocols,PPTP,L2TPAndIPSec, WherePPTPAndL2TPThe protocol works inOSIThe second layer of the model, also known as the second layer tunnel protocol;IPSecIt is a layer-3 tunnel protocol and the most common protocol.L2TPAndIPSecIt is currently the best and most widely used.
Sort by device type:
Network equipment providers develop different VPN network devices for different customer needs, mainly for vswitches, routers, and firewalls
1) router typeVPN: Vrovpn VPN is easy to deploy. You only need to add the VPN service to the vro;
2) Switch TypeVPN: It is mainly used to connect VPN networks with fewer users;
3) FirewallVPN: Firewall typeVPNIs the most commonVPNMany vendors provide this configuration type.
There are many methods to implement VPN, which are commonly used in the following four ways:
1) VPN Server. In a large Lan, you can build a VPN Server in the Network Center.
2) software VPN, which can be implemented through dedicated software.
3) Hardware VPN, which can be implemented through dedicated hardware.
4) Integrated VPN, many hardware devices, such as routers and firewalls, all contain VPN functions. However, hardware devices with VPN functions are generally more expensive than those without this function.