VPN blocking - Definition from the Hotspot Shield Glossary
Virtual Private Network blocking is the process of actively blocking a device or network from establishing a VPN tunnel by blocking any encrypted tunneling protocols.
VPN blocking can be implemented by corporations, governments or businesses as an additional security measure and to prevent unauthorized access to its sensitive information and network. There are various different methods of VPN blocking including closing the ports that are associated with VPN networks, blocking the IP addresses of known VPN providers, or even going so far as blocking all known overseas IP addresses. The continual battle between those who want to use VPN connections, and the organizations who want to block there use results in the development of more sophisticated technologies to aid both sides of the argument.