A Virtual Private Network (VPN) is programming that creates a secure and encrypted connection across a less secure network like the public internet
Remote access VPNs and site-to-site VPNs are the two most common types of VPNs.
Remote access VPN
Remote access VPN clients on the network of the organization connect to a VPN gateway server.
The gateway requires the device to authenticate its identity before accessing internal network resources like file servers,
Some VPNs provide access to the target network for Layer 2;
these require a tunneling protocol such as the Point-to-Point Tunneling Protocol or the Layer 2 Tunneling Protocol that runs across the IPsec base.
A site-to-site VPN, on the other hand, uses a gateway device to connect a whole network at one location to a network elsewhere.
Remote location end-node devices do not need VPN clients because the connection is handled by the gateway.
A VPN server still sits at the edge of the company network in a mobile VPN, allowing authenticated, authorized VPN clients to secure tunneled access.
However, mobile VPN tunnels are not associated with physical IP addresses. Instead, a logical IP address is attached to each tunnel.
Hardware VPNs offer a number of benefits over VPN based software. Hardware VPNs can provide load balancing to handle large client loads in addition to enhanced security. Using a web browser interface, the administration is managed.
A VPN appliance is a network device equipped with enhanced security features, also known as a VPN gateway appliance. Also known as a VPN SSL (Secure Sockets Layer), it is a router that provides protection, authorization
Dynamic multipoint virtual private network (DMVPN),
A Dynamic Virtual Private Network (DMVPN) multipoint is a secure network that exchanges data between sites without having to pass through the Virtual Private Network (VPN) server or router headquarters of an organization. A DMVPN basically creates a VPN mesh
VPN Reconnect is a Windows 7 and Windows Server 2008 R2 feature that allows a virtual private network connection to remain open during a short Internet service interruption. Usually when an Internet connection is dropped by a computer device using a VPN connection