A VPN uses various specific ports when tunneling your traffic over the internet. These ports are usually associated with the VPN protocol in use.
Thus, each VPN protocol has a different port that the VPN uses when establishing a connection over the internet.
In this article, you will learn what a port is, commonly used VPN ports, VPN port numbers, and associated VPN protocols, VPN ports to avoid, and port forwarding.
Let’s get started!
I begin by defining what a port is and then delve into the commonly used VPN ports, highlighting their respective protocols. The concept and application of port forwarding in VPNs are also discussed.
An important part of the article is dedicated to contrasting the two primary communication protocols associated with port numbers: TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
Towards the end, I enumerate certain VPN ports that are advisable to avoid and provide insights into why VPNs commonly favor UDP port 500 and TCP port 443, elaborating on the specific advantages these ports offer in the context of VPN usage.
Ports, in networking, are virtual communication conduits between connected devices or services.
Each port has a unique number that services or devices use to identify what type of traffic the port handles and its destination. This number is assigned by Internet Assigned Numbers Authority (IANA).
Port numbers use communication protocols and the host’s IP address for communication. Thus, a device can communicate using the set protocol and the port number to deliver a specific data type to a defined destination.
Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are communication protocols associated with port numbers. They define all the aspects of how the ports will exchange information.
These communication protocols have various strengths and weaknesses, so VPN protocols may choose to use one or both during tunneling.
Let’s see how they compare:
|Transmission Control Protocol (TCP)
|User Datagram Protocol (UDP)
|TCP is a connection-oriented protocol that must establish a connection between two endpoints before communication begins.
|UDP is a connectionless protocol that doesn’t need to establish a dedicated end-to-end connection for communication to begin.
|TCP is reliable. It ensures data reaches its destination by retransmission or the connection is dropped. No data will go missing.
|UDP is unreliable. After the data is sent, there’s no guarantee that it will reach its destination. No retransmission of lost data.
|TCP is heavy and has a longer variable header length.
|UDP is light and has a fixed header length.
|Data arrives as it was sent sequentially, such as in the case of first come, first served.
|Data doesn’t arrive in a sequence. Whichever data comes first will be received by the recipient.
|TCP cannot broadcast, and it can only send data bi-directional.
|UDP can broadcast, and it will send data to all available recipients.
|TCP has extensive error-checking mechanisms for data acknowledgment.
|UDP doesn’t acknowledge data and hence needs minimal error checking.
The above characteristics make each communication protocol unique in its functionality.
TCP always ensures data is delivered, which is slower due to its acknowledgments. Thus, TCP is used for reliability when speed is not a priority.
UDP is light, has no acknowledgments, and data arrives in any sequence. These characteristics make UDP a fast protocol. It is used when speed is a priority over reliability.
VPNs use port numbers as the VPN protocol in use defines them. Each VPN protocol may have one or more port numbers.
The more VPN protocols a VPN provider has, the more the pool of port numbers. However, only one VPN protocol suite can be used during tunneling.
Thus, the protocol will automatically select the port numbers to be used. Some VPN providers allow users to choose what port number to use, especially on the Open VPN protocol.
Here are the standard VPN protocols and their port numbers:
IKev2 and L2TP use the same ports as IPsec. This is because IPsec is usually paired with either of the protocols.
Other than the common VPN port numbers, some of the best VPN providers may offer configurations that use different port numbers. This is to facilitate speed or bypass VPN blocks.
Most VPN protocols are associated with UDP port 500 or TCP port 443. These port numbers are known for their speed and reliability and are rarely blocked.
UDP port 500 is connectionless and faster but doesn’t have the best security configurations. IKev2 and L2TP protocols usually use this port, which explains why they are fast.
UDP port 500 is also allowed to pass through firewalls and routers. This port is crucial for facilitating security keys used for secure communications.
TCP port 443 is used for HTTPS traffic. It makes secure connections over the internet and relies on other encryptions such as Transport Layer Security (TLS).
VPN protocols that use this port are known for reliability and security. Furthermore, this port is also allowed on most firewalls and routers.
Blocking this port also blocks HTTPS traffic; essentially, no one will have access to the secure network (internet).
Ports can be used by cybercriminals and other interested parties for traffic analysis, hacking, and exploiting other vulnerabilities within a system or a service.
The most common VPN ports used by premium VPNs are tweaked with some configurations to ensure they are secure from attacks.
However, some rogue VPNs, especially free and substandard VPNs, may implement connections using newer protocols or even untested frameworks with vulnerabilities.
Usually, these protocols use unsecure ports. These VPN providers do this to cut costs or facilitate easy access to your information.
Furthermore, if you like to open ports on your system, you should also avoid these ports. They include:
If you are not tech-savvy, it will be hard to know if some VPNs are using the above ports. To be secure, always use a premium, reputable VPN.
Port forwarding allows you to reroute traffic to another port. This is usually done to bypass firewalls or to improve your connection speeds.
Most VPNs allow for port forwarding to facilitate the use of other applications or services over the VPN connections.
Usually, port forwarding is used for remote access, torrenting, and online gaming.
Port forwarding offers convenience at the expense of your security – it makes your connection vulnerable to cyberattacks.
In some instances, it might not improve your connection speeds. When port forwarding, always prioritize security.
A few minutes for speed or convenience can compromise your privacy and security.
VPN ports play a crucial role in how the VPN securely tunnels your connections and traffic over the internet.
When not configured properly, they can be detrimental to your online security and privacy. Thus, if you are not tech-savvy, let your premium VPN choose the correct ports automatically.