CGNAT, or Carrier-Grade Network Address Translation, is a technique designed to extend the scalability of IPv4 networks while helping internet service providers (ISPs) conserve their limited IPv4 address pools.
Every online user operates with two IP addresses: a private IP and a public IP. Typically, the NAT (Network Address Translation) protocol converts private IPv4 addresses into public ones to enable online communication.
However, with CGNAT — also known as Large-Scale NAT (LSN) or NAT 444 — an additional layer of address translation is introduced. Here, unique private IP addresses are mapped into public IPs that are shared among multiple users. This approach allows ISPs to efficiently manage their IPv4 resources, effectively delaying the exhaustion of their address pools.
Understanding the difference between CGNAT and Non-CGNAT networks
The key distinction between CGNAT (Carrier-Grade Network Address Translation) and non-CGNAT networks lies in how IP addresses are allocated and shared.
Non-CGNAT Networks
In non-CGNAT networks, each device connected to the network is typically assigned its own unique static IP address. This dedicated IP allows for seamless, direct communication between devices on the same network without the need for translation or additional routing.
CGNAT Networks
On the other hand, CGNAT networks operate by sharing a pool of public IP addresses among multiple devices. Through NAT (Network Address Translation), a single public IP can represent multiple devices, enabling them to communicate. However, this shared approach introduces an additional layer of translation for device interactions.
Both systems serve their purpose, but they differ significantly in how they manage IP resources and facilitate connectivity.
What is NAT?
Network Address Translation (NAT) is a technique that enables multiple devices on a local area network (LAN) to share a single public internet IP address. NAT allows hundreds or even thousands of devices to connect to the internet and communicate seamlessly without requiring a unique public IP address for each device.
In addition to its role in IP address conservation, NAT enhances security by making internal networks invisible to external networks, offering protection against malicious cyber threats.
What is an IP Address?
An IP address (Internet Protocol address) is a unique numerical identifier assigned to every device connected to a computer network that uses the Internet Protocol for communication. It serves two primary purposes:
- Identifying a host or network interface.
- Providing location addressing.
Essentially, an IP address acts as a digital label, pinpointing the location of a specific device within a network.
What is a CGNAT IP address?
Your internet service provider (ISP) often assigns a public IP address that is shared among multiple users. This shared IP is known as a CGNAT (Carrier-Grade NAT) IP address and typically falls within the 100.x.y.z range.
If your current IP address belongs to this range, your ISP is likely employing CGNAT to conserve IPv4 addresses.
Can you bypass CGNAT?
Sticking with CGNAT is usually fine unless you need to forward ports for applications or games that require direct connectivity. Port forwarding can be challenging under CGNAT.
So, is it possible to bypass or opt out of CGNAT? Absolutely! Many ISPs allow users to opt out of CGNAT. You can contact your ISP’s technical support team and provide a valid reason to request removal from CGNAT. This will result in a new public IP address allocation. If you already have a static IP address, however, you don’t need to worry — static IPs aren’t affected by CGNAT.
Advantages of CGNAT
CGNAT offers several benefits, particularly for ISPs and network operators:
- Cost Efficiency: By sharing a single public IP address among multiple users, CGNAT minimizes the costs associated with managing IPv4 addresses.
- Enhanced security: It shields individual devices behind a single shared IP, making it harder for malicious actors to directly target specific users.
- Scalability: CGNAT allows ISPs to accommodate more users without requiring additional public IP addresses.
- Network congestion reduction: Pooling users beneath a single IP address helps reduce overall data traffic, ensuring consistent performance during peak usage periods.
- Accessibility: CGNAT facilitates access to services that might otherwise be unavailable due to IPv4 scarcity.
