By Miklos Zoltan . 3 July 2024
Founder - Privacy Affairs
Justin Oyaro
Fact-Checked this
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!
Summary: This article explores the role of VPN ports in channeling internet traffic and their significance in secure communication. It begins by defining what a port is, highlighting their importance in managing and directing internet traffic efficiently.
Commonly used VPN ports include Port 1194 for OpenVPN, Port 1701 for L2TP, Port 1723 for PPTP, and Port 500 for IKEv2. Port forwarding, which involves redirecting communication requests to enhance performance and security, is also discussed.
The article contrasts two primary communication protocols associated with port numbers: TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). TCP is connection-oriented and ensures reliable, ordered delivery of data packets, while UDP allows faster, connectionless transmission, prioritizing speed over reliability.
Certain VPN ports are advisable to avoid due to vulnerabilities or suboptimal performance. In contrast, UDP Port 500 and TCP Port 443 are favored for their specific advantages. UDP Port 500 is efficient for IKEv2 connections, and TCP Port 443 can bypass network restrictions and firewalls by using the standard port for HTTPS traffic.
Understanding the role of VPN ports and their associated protocols is crucial for optimizing VPN performance and ensuring secure communication. By leveraging the strengths of TCP and UDP and avoiding less secure ports, users can enhance their VPN experience.
What are VPN Ports?
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.
Communication Protocols: TCP vs. UDP
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.
Common VPN Port Numbers
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:
- OpenVPN: This protocol uses TCP port 443 and UDP port 1194. It is the gold industry standard for VPN protocols with speed and reliability.
- WireGuard: This protocol uses UDP port 51820 by default. It is the newer protocol on the block – it is faster and more secure.
- SoftEther: SoftEther VPN Protocol (Ethernet over HTTPS) uses TCP Ports 443, 992, and 5555. The SoftEther VPN mostly uses this protocol.
- IKEv2: Internet Key Exchange version 2 protocol uses UDP port 500 and port 4500. This protocol is mainly used for mobile VPN connections.
- IPsec: Internet Protocol Security uses UDP port 500 and port 4500. This protocol offers encryption to other tunneling protocols.
- SSTP: Secure Socket Tunneling Protocol uses TCP port 443. Although it is not offered nowadays, SSTP bypasses restrictions.
- L2TP: Layer Two Tunneling Protocol uses port numbers such as TCP port 1701, UDP port 500, and port 4500.
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.
Why Do VPNs Prefer UDP Port 500 and TCP Port 443?
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).
VPN Ports to Avoid
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:
- TCP port 21: Used for FTP. Vulnerable due to the unencrypted nature of the involved transmission.
- TCP port 23: Used for Telnet remote operations. The text communications are unencrypted
- TCP/UDP port 53: Used for zone transfers for maintaining the DNS database. Hackers can use it to target vulnerabilities in the DNS database.
- TCP port 80: Used for HTTP, which is not secure.
- TCP port 1080: Used for SOCKS internet proxies. Hackers can use the proxy for their malicious activities.
- TCP port 4444: This is the listening port for Metasploit – a project used for penetration testing. It can also be used for hacking.
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.
What is Port Forwarding?
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.
Wrap Up
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.
Founder & CEO Privacy Affairs
Miklos Zoltan is the founder and CEO of Privacy Affairs. Miklos has long-time experience in cybersecurity and data privacy having worked with international teams for more than 10 years in projects involving penetration testing, network security and cryptography.
Miklos founded Privacy Affairs in 2018 to provide cybersecurity and data privacy education to regular audiences by translating tech-heavy and "geeky" topics into easy-to-understand guides and tutorials.
