CGNAT (Carrier-Grade NAT)

Definition: Carrier-Grade Network Address Translation (CGNAT) is a large-scale version of the NAT process that happens inside your home router. It is used by Internet Service Providers (ISPs) to share a single, public internet IP address among hundreds or thousands of different customers.

Why it matters in Bangladesh: Because there are not enough unique IPv4 addresses for every internet user in the world, almost all ISPs in Bangladesh use CGNAT by default for home broadband connections. While this keeps internet costs low and allows for rapid expansion, it prevents users from doing things like port-forwarding for CCTV cameras or achieving an “Open NAT” type in online gaming.

How to fix it: If CGNAT is causing issues with your gaming or remote access, you must contact your ISP and pay a small monthly fee to be assigned a Dedicated (Real) IP address, which bypasses the CGNAT system.

Related Terms:

• NAT
• Real IP vs Shared IP