Making Less More: The CGNAT IP Address

In the final blog for our “What is” IP Address series, we discuss what our Customer Support team says is one of the most frequent questions they get from users: What is a CGNAT IP Address?

Basics

CGNAT, also known as CGN, stands for Carrier Grade Network Address Translation. It is used by Internet Service Providers (ISPs), predominantly mobile and Satellite carriers, to allow numerous devices to coexist and share a small number of public IP addresses. CGNAT also offers a higher tier of security compared to NAT.

As we mentioned in a previous blog, the pool of available IPv4 addresses is becoming more limited. While IPv6 addresses helps solve this issue by replacing IPv4, it isn’t backward compatible with IPv4. In fact, updating network equipment to IPv6 is a very involved process that can be expensive to boot. CGNAT is a solution to this problem.

How Does it Work?

ISPs will use CGNAT in order to provide support to millions of users: CGNAT is a large-scale NAT that converts IPv4 addresses that are private to public. They do this by using Network Address and Port Translation methods to combine numerous private IPv4 addresses into fewer public IPv4 addresses. Therefore, CGNAT creates a limit on the use of public IP addresses of an organization by allowing them to share one public IP address in order to support many private IP addresses.

Because it is able to support just a large amount of users at once, you can image that the implementation process is a lot more complex.

Important Notes About CGNAT:

IPv6

Although CGNAT is crucial for managing the IPv4 address shortages, it comes with limitations and challenges. The transition to IPv6 is inevitable.

Latency

The additional translation layer can introduce latency, potentially affecting the performance of real-time applications like gaming or video conferencing.

Port Forwarding

It is important to research what options an ISP has to offer when it comes to Port Forwarding. Sharing IP addresses means fewer ports are available per user, which can impact applications that require multiple ports.

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Questions? Feel free to reach out to our awesome Customer Support team here.