What are VPN ports?
A VPN port is a network communication endpoint that VPN protocols use to transmit encrypted data packets between a VPN client (your device) and a VPN server. VPN ports use numeric identifiers that operating systems rely on to deliver that encrypted traffic to the correct VPN service on both your device and the server. Ports themselves are not specific to VPNs — all networked applications use ports to send and receive data. Each port acts as an endpoint within the TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) layers of the network, allowing the VPN protocol to exchange data with the correct device and application.
Every VPN protocol operates over TCP or UDP, and the protocol design or server configuration defines which port it uses. UDP usually supports faster performance, while TCP helps the connection handle network rules. So, for example, OpenVPN will often use UDP port 1194 for consistent speed, though it can run on many other ports depending on configuration, while IPsec/IKEv2 will rely on UDP 500 and UDP 4500 to handle key exchange.
How VPN ports work
VPNs use ports because each protocol needs a numeric identifier that tells the operating system which VPN service should receive the encrypted traffic.
When you connect to a VPN, the VPN app encrypts outgoing traffic and sends it through a port defined by the VPN client or server configuration. The data packets then travel through routers, firewalls, and other network layers until they reach the correct destination. Each device on the path identifies the traffic by its port and forwards it to the proper host.
The VPN server then decrypts the requests, relays them across the internet, receives responses, and returns them through the same VPN port. This cycle keeps your internet traffic protected while maintaining a steady connection.
When you measure how effectively a port works, you look at:
- Speed. UDP ports avoid overhead, which increases performance.
- Reliability. TCP ports add verification, which helps the connection withstand packet loss.
- Firewall traversal. Ports like 443 blend in with HTTPS traffic.
- Stability. Some ports hold a VPN session more consistently on mobile networks.
What are VPN port numbers?
Every device connected to an online network will have a unique IP address. Port numbers exist to indicate several different operations happening under each address. In short, port numbers help the destination device determine which application or service should receive the incoming data.
Many common services use well-known default port numbers. For example, a file transfer protocol uses port number 20 for data transfers. Depending on how you’ve configured your port-forwarding rules, the software reads the port number, determines which application or service should receive the traffic, and then sends the data there.
Without ports, devices could still communicate over a network, but only one application per transport protocol could do so at a time, since ports allow multiple connections to share the same IP address.
What are the common VPN ports?
Different VPN protocols rely on different default port choices based on how they are typically deployed and how networks handle their traffic. While these protocols can often run on other ports if configured that way, their commonly used ports reflect practical needs such as performance, firewall compatibility, and NAT traversal. For example, UDP suits fast VPN traffic, while TCP supports strict reliability checks.
NordVPN implements the OpenVPN protocol. The open-source nature of this protocol means it’s continually being tested for security loopholes by devs. For NordVPN to work on your network, your router needs ports 1194 UDP and 443 TCP to be open.
Below is a list of the most often used VPN protocols — the port numbers that must be open for the software to work.
| VPN protocol | Transport type | Port numbers used | Description |
|---|---|---|---|
| UDP | Port 51820 | Supports fast and efficient encrypted traffic with low overhead. | |
| UDP | Port 1194 | A default OpenVPN port that improves speed and reduces latency. | |
| | TCP | Port 443 | Matches HTTPS traffic patterns to work on network filters. |
| IKEv2 | UDP | Port 500 | Handles IKE key exchange during connection setup. |
| | UDP | Port 4500 | Supports NAT traversal when devices sit behind routers that modify addresses. |
| UDP | Port 500 | Manages authentication and key exchange for IPSec sessions. | |
| | UDP | Port 4500 | Enables IPSec to function across NAT devices without interruption. |
| TCP | Port 1723 | Required by the PPTP control connection and tied to its outdated architecture. | |
| TCP | Uses SSL-like traffic to work on filtered networks. | ||
| UDP | Port 500 | Works with IPSec during initial setup. | |
| | UDP | Port 4500 | Allows L2TP/IPSec to run behind NAT devices. |
| | UDP | Port 1701 | Establishes the base L2TP tunnel before IPSec protects the traffic. |
What is port forwarding?
Port forwarding is a technique that allows external devices or computers on the internet to communicate with specific services or applications running on devices within a local network by directing incoming traffic on a chosen port to that internal device. Port forwarding does not create a separate data stream or bypass security software by default, but it does expose the selected port to the internet. Whether this process creates risk depends on how securely the service listening on that port is configured and maintained. If you’re still curious, read this port forwarding guide.
NordVPN is not compatible with any form of port forwarding. Port forwarding requires certain ports to be open, whereas NordVPN closes off all ports that aren’t needed to create a secure connection environment.
Do you need to configure VPN ports yourself?
Most users never need to configure VPN ports manually. Your VPN provider chooses the correct default port automatically and adjusts settings during a VPN session. This way, the provider can guarantee a stable and safe VPN connection. Changing ports without experience can break the connection instead of improving it. Even more, most providers won’t let you change ports unless they support port forwarding.
You’d only need to configure ports manually when:
- You run your own VPN server.
- You manage a site-to-site VPN.
- Your firewall or network administrator requires specific ports to open.
Which ports should you avoid?
No single VPN port exists that you can guarantee is 100% secure. What’s available is a selection of ports and protocols with varying degrees of security, and these protocols happen to use certain ports.
The security of a port depends on the service running on that port and its configuration. The port number itself does not determine the security level. It’s essential to ensure that all services, regardless of the port, are properly secured and regularly updated to mitigate potential security risks.
When it comes to your online security and privacy, you can’t skip corners. Do your research and make an informed decision as to what VPN service you should choose. After all, a premium product warrants premium service. NordVPN is the world’s leading VPN for a reason — unparalleled and unbeatable coverage. With 8,900 servers in 129 countries, you’re never too far from a safe and secure internet connection.
Online security starts with a click.
Stay safe with the world’s leading VPN
