Virtual Private Networks and Remote Access

IPSec VPNs

operate at layer 3, require a client, and can operate in either tunnel or transport mode. In tunnel mode, entire packets of data sent to the other end of the VPN connection are protected. In transport mode, the IP header is not protected but the IP payload is

SSL VPNs

can either use a portal-based approach (typically using HTML5), where users access it via a web page and then access services through that connection or they can offer a tunnel mode like IPSec VPNs

Remote-access VPNs

are commonly used for traveling staff and other remote workers, and site-to-site VPNs are used to create a secure network channel between two or more sites

Site-to-site VPNs

are frequently always-on VPNs, meaning that they are connected and available all the time, and if they experience a failure they will automatically attempt to reconnect

Remote-access VPNs

are most frequently used in as-needed mode, with remote workers turning on the VPN when they need to connect to specific resources or systems or when they need a trusted network connection