Is CGNAT Port Forwarding Possible – Let’s Find Out

About Is CGNAT Port Forwarding Possible? When internet services came onto the scene, there were 4 billion IPv4 addresses. 

As such, ISPs could provide each internet-connected device with a unique IP address. 

However, as the internet became popular, these IPv4 addresses became scarce and expensive. 

To navigate this issue, ISPs started using CGNAT to facilitate several customers’ sharing of a single IP. 

While CGNAT allows ISPs to serve several customers with scarce IPv4 addresses, it brings a problem to individuals wanting unrestricted network access.

 In this article, we define CGNAT and offer a few CGNAT port-forwarding solutions to help you use your network flexibly.

What is CGNAT

Courier Grade Network Address Translation, or CGNAT, is an ISP technique to conserve IPv4 IP addresses. 

Before we discuss it in detail, let’s first understand the three last characters of CGNAT, i.e., the NAT.

 Every device in your LAN has a unique IPv4 address, say, which it uses to communicate with your router. 

Now, your router probably uses NAT to share its public IP address with all the devices in your LAN.

 Your router keeps NAT data to know which device sent which request to connect it to the right client.

CGNAT is a large-scale NAT used by newer ISPs such as Starlink and cellular ISPs to share a single public IPv4 IP address. 

While this technique increases the number of internet users by sharing one IP address among many clients, it has limitations.

 For instance, you can’t host services from home, are unable to establish peer-to-peer connections and have challenges when establishing an incoming connection. 

IP addresses

IP addresses

Is port forwarding possible with CGNAT?

Typically, port forwarding with CGNAT is not possible. Port forwarding directs incoming internet traffic to a certain device or service within a local private network. 

For example, forwarding ports to a security camera system, an internet server, or a gaming console like PS5. 

For it to work, you must specify the port where the internet traffic will be forwarded. It, therefore, means your router must have a routable public address. 

But, this is not the case with the CGNAT network. In CGNAT, each router in the ISP network is assigned a private address, making it inaccessible from the Internet. 

In turn, the ISP assigns a single public IP address to different routers, and it’s impossible to specify where to send traffic when port forwarding. 

However, there are several workarounds to this CGNAT port forwarding issue, as I discuss below.

IP routing table

IP routing table

CGNAT Port Forwarding Solutions

I recommend choosing an ISP with a public IP address as the best way to solve the CGNAT port forwarding problem. 

However, this is not always possible since most popular ISPs such as Verizon, HughesNet, and Starlink do not offer Public IP options. 

Therefore, if you wish to use the services of these popular ISPs, consider the following solutions for CGNAT port forwarding:

A Virtual Private Network, abbreviated as VPN, refers to a technology that offers a private and secure connection over the Internet. 

The VPN service establishes encryption between your devices and the VPN server, giving your internet activity anonymity and security. 

You can run a VPN program on your laptop, smartphone, or other internet-enabled device. 

Doing so gives you a public IP address that you can use to bypass CGNAT. 

A VPN also allows you to bypass geo-restrictions by connecting to a VPN server in the country you want to access.

Additionally, it masks your real IP, thus keeping your browsing anonymous and private.

 What’s more, it is a way of preventing malicious network interceptions when using a public network.

Apart from installing a VPN on your network-enabled device, you can also install it on your router. 

This way, you can use the VPN on all your LAN devices and enable port forwarding as in ISPs offering a public IP. 

 However, your router must have an inbuilt VPN functionality. 

VPN Installation Process

Setting up a VPN on any of your devices is easy, and you can do it with the following process:

  • Identify the right VPN considering some factors such as speed, prices, and location of the servers.
  • Download and install the VPN software on your laptop, smartphone, or any other device.
  • Check your IP address before connecting to the VPN.
  • Now register with your client’s VPN as required on their website.
  • The next step is to log in using your set credentials.
  • Then, connect to the VPN server of your choice. Most VPNs allow connection to servers in different countries and locations depending on your subscription.
  • Check your IP address after connecting to the VPN. If it has changed, you have bypassed the CGNAT.
  • Now, you can port forward your traffic as you desire.

Note that VPNs comes at a monthly fee and are prone to slow internet connection due to longer traffic route and the encryption procedure. 

Additionally, VPNs change IP address each time you connect, which poses a problem when hosting servers requiring static IP addresses.

Using a Proxy Server

A proxy server acts as a go-between between your device and the server where you see resources. 

When you connect to a proxy server, you use the server IP, thus masking your real IP, which can help you bypass CGNAT. 

You can get several premium and free proxy servers, such as Squid and Apache HTTP.

 After choosing the appropriate proxy server, then configure your device to router your traffic through the server. 

However, note that proxies may not encrypt your data like VPNs do.

Proxy server and VPN concept

Proxy server and VPN concept

Using IPv6

IPv6 has been around for usage, but not many ISPs use it for various reasons. It is typically an upgrade of IPv4, offering trillions of public IP addresses. 

While ISPs are yet to migrate to this upgraded public IP, upgrading would ensure enough public IP for each device. 

Therefore, the first step is to check if your ISP allows IPv6. Then, change your IP network settings from IPv4 to IPv6, and you can bypass CGNAT.

How to Choose a Suitable VPN Service for CGNAT Port Forwarding

When selecting a VPN service for CGNAT port forwarding, you need to consider the following factors:

  • Ensure your VPN client supports the port forwarding feature since not all services support this functionality.
  • Choose a VPN service with servers close to your resident area or country. When servers are near, you eliminate latency and lagging connection issues.
  • Before subscribing to a VPN service, ensure the provider has a reputation for high performance regarding connection speed. This consideration is vital when hosting services such as games, apps, or servers that require a stable connection.
  • Finally, consider the responsiveness and helpfulness of the customer support of your VPN client. Ensure you can reach them conveniently via contact, live chat, emails, and other comprehensive troubleshooting ways.

VPN concept


While CGNAT port forwarding is typically impossible, you can eliminate this problem using various methods.

According to our discussion, the best and most easily applicable technique is using a VPN.

However, consider the above factors to choose the most appropriate VPN.