Want to know whether your internet connection uses Carrier Grade NAT (CGNAT)? Compare the WAN IPv4 address assigned to your router with the public IPv4 address visible to websites. This helps identify whether your connection may be behind an internet service provider’s address-sharing system.
Our Carrier Grade NAT Checker uses the addresses you enter to identify common signs of CGNAT, private network addressing, and other upstream NAT configurations. It does not automatically access your router or confirm your ISP’s network configuration.
Carrier Grade NAT Checker
Compare your router's WAN IPv4 with the public IPv4 seen by websites.
How to use this checker
- Connect your device to the home network or router you are testing.
- Sign in to your router using its actual management address. Find WAN, Internet, or Connection Status.
- Copy the WAN IPv4 address, not the local router IP.
- Look up your public IPv4 on the same connection and enter both addresses above.
- Read the result and ask your ISP to confirm CGNAT if needed.
Privacy: This checker processes the two entered IPv4 values in your browser and makes no network request of its own. Normal WordPress hosting, security tools or analytics may still log page visits. IPv6 is not assessed.
What Is Carrier Grade NAT (CGNAT)?
Carrier Grade Network Address Translation, commonly called CGNAT, is a technology that allows an internet service provider (ISP) to share one public IPv4 address among multiple customers.
Normally, a home router translates traffic between private addresses used by devices inside your home and an address assigned to its internet connection. With CGNAT, the ISP performs additional address translation within its own network.
CGNAT helps providers conserve limited IPv4 addresses. For most everyday activities, including browsing, video streaming, messaging, and ordinary downloads, it can work without noticeable problems.
However, CGNAT can make it harder to establish incoming IPv4 connections to devices or services running inside your home network.
How to Check If Your Internet Uses CGNAT
You need two pieces of information: your router’s WAN IPv4 address and the public IPv4 address seen by websites.
Step 1: Find Your Router WAN IP Address
- Connect your computer or mobile phone to the Wi-Fi network you want to examine.
- Open your router’s administration page. Depending on your device, examples of local management addresses include
192.168.1.1and192.168.0.1. - Sign in using your authorized router administrator credentials.
- Look for a section labeled Internet, WAN, Connection Status, or Network Status.
- Find the WAN IPv4 or Internet IPv4 address and copy it.
The exact steps depend on your router or optical network terminal (ONT). Use the device manual or the address provided by your ISP if the examples above do not work.
Important: The router’s LAN or gateway IP address is different from its WAN address. Do not enter the LAN address merely because it appears in your browser’s address bar.
Step 2: Find Your Public IPv4 Address
While connected to the same internet connection, open a public IPv4 lookup service in your browser.
Copy the displayed IPv4 address. If the service shows an IPv6 address, select its IPv4 result instead.
For a meaningful comparison, avoid using a VPN, proxy, or another network connection that changes the address websites see. Do not disable an organization-managed VPN without permission.
Step 3: Compare Both Addresses
Enter your router’s WAN IPv4 address into the first field of the checker above. Add the public IPv4 address to the second field.
Select Check NAT indicators to see the result.
The tool examines the entered address ranges and checks whether the two addresses match. It does not run a port scan, contact your ISP, or automatically retrieve information from your router.
Understanding Your CGNAT Checker Results
| Result | What it means |
|---|---|
| CGNAT is likely | The WAN address belongs to the shared IPv4 range 100.64.0.0/10, commonly used in CGNAT deployments. |
| Upstream NAT indicated | The WAN address is private. Another router or ISP-side translation may be involved. |
| No IPv4 CGNAT indicated | Your router’s public-looking WAN IPv4 matches the public IPv4 you entered. |
| Comparison incomplete | More information is needed to assess the connection. |
| Inconclusive or special-use address | The addresses do not support a reliable CGNAT determination. |
What Is the 100.64.0.0/10 IP Range?
The address range from 100.64.0.0 to 100.127.255.255 is reserved as shared IPv4 address space under IETF RFC 6598.
It is commonly used between customers’ network equipment and service-provider CGNAT systems.
If your router receives a WAN IPv4 address within this range, CGNAT is a strong possibility. Your ISP can confirm how your connection is configured.
What If Your WAN IP Is Private?
A WAN address beginning with 10, belonging to 172.16 through 172.31, or beginning with 192.168 is within the private IPv4 ranges defined by RFC 1918.
This often indicates another private network between your router and the internet.
For example, if you use both an ISP-provided ONT and your own Wi-Fi router, the ONT may already be performing NAT. This is commonly called double NAT.
A private WAN address alone cannot establish whether the additional translation is managed by your own equipment or by the ISP.
What If Both IP Addresses Match?
If the WAN IPv4 shown by your router matches the public IPv4 reported by an external website, your router appears to have the public-facing IPv4 address for that connection.
That is a useful indication that ordinary CGNAT is not present on that IPv4 path.
However, matching addresses do not guarantee that incoming connections will work. Router firewalls, ISP restrictions, software settings, and port-forwarding rules may still prevent access.
CGNAT vs Double NAT: What Is the Difference?
CGNAT and double NAT can produce similar symptoms, but they are not necessarily the same thing.
CGNAT generally refers to address translation performed inside the service provider’s network, potentially allowing many subscribers to share public IPv4 addresses.
Double NAT means that traffic passes through two NAT devices or translation layers. One common home example is a Wi-Fi router connected behind another router.
CGNAT deployments can also create multiple layers of NAT.
The distinction matters because a home double-NAT configuration may sometimes be corrected by changing supported router settings. ISP-managed CGNAT generally requires assistance from the provider or an alternative remote-access method.
Does CGNAT Affect Gaming, CCTV or Remote Access?
CGNAT does not automatically make an internet connection slow or unsuitable for gaming. Many online games and applications establish outbound connections and can work normally.
The main difficulty appears when a service requires unsolicited incoming IPv4 connections.
Online Gaming
CGNAT may affect peer-to-peer connections, particular multiplayer features, or the ability to host game sessions. Its effect depends on how the game handles network connections.
A strict NAT status in a game is not conclusive proof of CGNAT. Local firewall restrictions and home router configurations can produce similar results.
CCTV and Security Cameras
Some CCTV systems depend on direct inbound connections to a recorder or camera network. Such setups may not work through CGNAT without additional support.
Other systems use outbound cloud connections and may work without a public IPv4 address.
Avoid exposing camera administration interfaces directly to the internet. Use secure, supported remote-access methods whenever possible.
Home Servers and Port Forwarding
Running a self-hosted game server, file server, or other remotely accessible service can be difficult behind CGNAT.
Creating a port-forwarding rule on your home router does not automatically create a corresponding rule on the ISP’s CGNAT equipment.
Where supported, a secure VPN, a properly configured remote-access service, or an ISP-provided public IP may be more suitable.
How to Resolve CGNAT-Related Problems in Pakistan
If the checker suggests CGNAT and you need incoming IPv4 connectivity, first confirm the result with your internet service provider.
Contact Your Internet Provider
Ask whether your connection uses CGNAT and whether the provider offers a public IPv4 option.
You can ask:
- Is my broadband or mobile connection using CGNAT?
- Can I obtain a public IPv4 address for remote access?
- Is a static public IP available on my current package?
- Are there additional charges or package requirements?
- Does my connection support IPv6?
Availability and policies vary by provider, package, and network. Do not assume that every PTCL, fibre broadband, or mobile connection uses the same address-assignment method.
Check for Double NAT at Home
If your internet equipment includes an ONT, modem, and separate router, check which device receives the ISP connection.
In certain configurations, supported bridge or passthrough settings may help remove an unnecessary layer of home NAT.
Do not change bridge mode, routing, or authentication settings unless you understand your equipment and have the necessary ISP configuration details. Incorrect changes can disconnect your internet service.
Consider IPv6
IPv6 is another possible option for applications requiring direct connectivity.
Having CGNAT on IPv4 does not automatically mean IPv6 connections are unavailable. Actual access depends on your provider, device support, IPv6 routing, and firewall rules.
The checker on this page only evaluates IPv4 information.
Can You Check CGNAT on a Mobile Network?
Checking CGNAT on mobile data is more difficult because a smartphone generally does not expose the carrier-side WAN address in the same way that a home router displays its internet connection details.
You can see the public IPv4 address used by your mobile connection, but that address alone cannot reliably determine whether the carrier uses CGNAT.
For mobile internet connections, contact your operator if you need inbound IPv4 connectivity or support for a specific remote-access application.
Frequently Asked Questions
Can CGNAT Be Detected Using Only a Public IP Address?
No. A public IPv4 lookup shows the address visible to the internet, but it does not reveal whether another device or the ISP is translating traffic before it reaches that address. Comparing it with the router WAN IPv4 provides better evidence.
Is CGNAT the Same as a Private IP Address?
No. CGNAT is an ISP-side address translation system. Private IPv4 addresses are address ranges used within private networks. CGNAT may use shared or private addressing, but having a private IP does not automatically prove CGNAT.
Can Port Forwarding Work Behind CGNAT?
Ordinary port forwarding on your router usually cannot, by itself, make a service reachable through an additional ISP-controlled NAT layer. Some providers may support particular inbound mapping arrangements or offer public-IP options.
Does CGNAT Reduce Internet Speed?
CGNAT is not, by itself, proof of a slow internet connection. Real-world performance depends on the provider’s network, equipment capacity, congestion, routing, and other factors. An internet speed test measures a different aspect of your connection.
Is a Public IP Always Static?
No. A public IPv4 address can be dynamic and change over time. A static public IPv4 is an address intended to remain assigned rather than changing through ordinary reconnections or reassignment.
Final Check: What Should You Do Next?
If your WAN IPv4 falls within 100.64.0.0/10, contact your ISP to confirm whether CGNAT is enabled.
If your WAN IPv4 is private, check whether another router or ONT is performing NAT.
If both public IPv4 addresses match but remote access still fails, review the firewall, port-forwarding settings, and application configuration rather than assuming CGNAT is responsible.
About this checker: NetTools Pakistan is an independent internet information website, not an official PTCL or PTA service. This tool compares manually supplied IPv4 addresses in your browser. It cannot inspect your provider’s network or guarantee a particular NAT configuration.
Technical References
- RFC 6598: IANA-Reserved IPv4 Prefix for Shared Address Space
- RFC 1918: Address Allocation for Private Internets
- RFC 6888: Common Requirements for Carrier-Grade NATs