What is CGNAT and why mobile IPs are so trusted

An IPv4 address is a 32-bit number: there are about 4.3 billion in total, and some are reserved for special uses. For years now the regional registries that hand them out have had no free stock left. A carrier with millions of customers can't give every phone a public IPv4.

Your home router already does something similar: all your devices reach the Internet through one public IP, and the router tracks which connection belongs to whom. CGNAT is the same idea inside the carrier's network:

1. The phone gets a private address inside the carrier's network (often in 100.64.0.0/10, a block reserved for CGNAT).
2. When it opens a connection to the Internet, carrier equipment translates it to one of the carrier's public IPs, with a different port for each connection.
3. At any moment, one public IP carries connections from many different phones.

To a website, a single mobile IP can therefore stand for a large number of real people browsing from the same area on the same carrier.

Anti-fraud systems give every IP a risk score. Blocking a datacenter IP is cheap: there's a server behind it, not customers. Blocking a mobile IP can cut off dozens or hundreds of legitimate users at once, costing sales and causing complaints.

So mobile IPs usually get softer, temporary limits, and websites rely more on other signals (cookies, browser fingerprint, behaviour) to tell users apart.

IPv6 has no shortage of addresses: each device can have its own public address, often inside a block (prefix) assigned to that connection. Websites account for this by reasoning per prefix rather than per address.

Modern mobile networks are dual stack: the phone has both an IPv6 and an IPv4 behind CGNAT. A dual-stack mobile proxy lets you use both, and the website picks whichever it supports.

• The IP is credible from day one: you don't need to "warm it up" like a datacenter IP.
• Changing IP is natural: phones change address all the time as they move and reconnect, so rotation doesn't look odd.
• Geolocation is approximate: mobile IPs are often located at the city of the carrier's node, not the phone's real position. That's normal and happens to real users too.
• The rest of your profile matters: timezone, language and TCP/IP fingerprint should match a mobile user in that country.