CGNAT
CGNAT (Carrier-Grade NAT) is a technique ISPs use to share one public IPv4 address across many customers at the same time, instead of giving each household or mobile subscriber its own address. It exists because the global supply of IPv4 addresses ran out faster than IPv6 rolled out everywhere, and it is especially common on mobile networks. The tradeoff is that anything tied to "your IP" -- blacklist status, inbound port forwarding, geolocation -- is really tied to everyone sharing that address with you. RFC 6598 reserves the 100.64.0.0/10 block specifically so CGNAT traffic can be told apart from ordinary private addressing.
By AdminKit team, Netbase JSC · Updated