CGNAT //
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AM I BEHIND
CGNAT?
Paste the WAN IP your router shows. The page compares it with the public IP the Internet sees and tells you whether there is CGNAT, double NAT or a direct public IP.
Your browser reached us over IPv6, so the IPv4 field is empty. Run curl -4 https://bithappens.com.br/ip and paste the result.
Where to find the WAN IP
- Open the router admin page (often 192.168.0.1 or 192.168.1.1) and look for WAN, Internet or Status.
- On the provider ONT, the field may be called "IP da WAN", "External IP" or "PPPoE IP".
- Without router access: run tracert -d 8.8.8.8 (Windows) or traceroute -n 8.8.8.8 and look at hops 2 and 3. A 100.64.x.x to 100.127.x.x address there points to CGNAT.
Frequently asked questions
What is CGNAT?
Carrier-grade NAT means the provider puts many customers behind the same public IPv4 address. Your router gets an address from 100.64.0.0/10 instead of its own public IP.
How do I know if I am behind CGNAT?
Compare the WAN IP your router shows with your public IP. If the WAN is between 100.64.0.0 and 100.127.255.255, it is CGNAT. If it equals your public IP, it is not.
Does CGNAT block port forwarding?
Yes, for inbound IPv4 connections. Forwarding ports on your router does not help because the provider NAT drops the connections first. IPv6, a paid public IP or a tunnel solve it.
What is double NAT?
Your router gets a private IP (192.168.x.x, 10.x.x.x) from another device, usually the provider modem/ONT in router mode. Putting that device in bridge mode usually fixes it.
How do I get out of CGNAT?
Ask your provider for a public IPv4; many offer it free or as an add-on. For cameras, servers and remote access, IPv6 or a VPN with a public exit also work.