VPNs are widely used to connect restricted or banned endpoints on the Internet. Whether it is used for corporations to ensure secure tunneling across their network or whether Internet users all around the world for accessing restricted content, it is an essential element for secure connections.
While VPNs can be used in your favor, your ISP, government, or even websites can build a wall by using a VPN block for various reasons. These reasons are likely to be government censorship, copyright, school and workplace restriction, and location restrictions. For example, internet providers in China perform Deep Packet Inspection for detecting and blocking VPN traffic.
VPN blocks are essentially tools that can detect VPN usage and deny access. It is a technique for blocking encrypted protocol tunneling. There are various methods for building a VPN block and even more for bypassing them.
Types Of VPN Block
Whether you want to use it across your corporate network or you are casually surfing on the Internet, a VPN block can either deny your access or help to restrict unwanted, unauthorized access. There are various reasons for VPN block usage.
Essentially, it is used as a prevention method for blocking access to certain restricted or banned endpoints across a network. And there are different types of constructing a VPN block to do so. The main methods of VPN blockage include IP blocks, Deep Packet Inspection (DPI), and Port blocking.
IP blocks restrict IP addresses that VPN providers use directly. So, certain VPNs are blocked straightforwardly. When an internet service provider or a website detects internet protocol addresses and identifies them as blocked ones, you cannot get access to restricted endpoints with a VPN whatsoever.
Another method of blocking a VPN is Deep Packet Inspection. DPI is a method of detailed packet filtering to examine the traffic of a network. While a regular packet inspection analyzes the headers of the data flow solely, a deep packet inspection analyzes the codes and details of data packets and determines what to do with them.
Additionally, DPI can detect applications, data usage behaviors, and even VPNs. So, the moment deep packet inspection detects certain codes and data of VPN usage, it blocks access or stops the activity.
Another method of VPN block is port blocking. As its name suggests, port blocking restricts certain ports from accessing to Internet. VPNs are using specific ports of UDP and TCP when establishing an Internet connection. So basically, ports can be monitored for filtering out VPN connections.
Methods Of Bypassing VPN Blocking
Although VPNs are instruments to gain access to restricted areas on the Internet, internet service providers, the government, or even websites can block VPNs. While there are various methods to stop a VPN from accessing specific endpoints, numerous bypassing methods also exist.
Additionally, to guarantee VPN connections are undetected, the methods include getting a static IP address, using obfuscated VPN servers, port switching, changing VPN protocols, and simply changing servers.
Source: What Is A VPN Block? - StartupGuys.net
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