CGNAT Explained

Fresh

Understanding Carrier-Grade NAT and why it makes mobile proxies so powerful.

What is CGNAT?

Carrier-Grade NAT (CGNAT) is a technique mobile carriers use to share limited IPv4 addresses among thousands of subscribers.

Why Carriers Use CGNAT

The IPv4 Shortage

Fact	Number
Total IPv4 addresses	~4.3 billion
Global mobile subscribers	~8 billion
Result	Not enough IPs for everyone

Carriers solve this by:

1. Assigning private IPs to devices (10.x.x.x range)
2. Translating to shared public IPs at the gateway
3. Using port numbers to track individual sessions

How It Works

Your Phone                    CGNAT Gateway                 Internet
─────────────────────────────────────────────────────────────────────
10.0.0.1:54321  ──────►  203.0.113.45:10001  ──────►  google.com
10.0.0.2:54322  ──────►  203.0.113.45:10002  ──────►  facebook.com
10.0.0.3:54323  ──────►  203.0.113.45:10003  ──────►  twitter.com

Each device gets a unique port on the shared public IP.

Why CGNAT Benefits Proxies

1. Shared Trust

When 10,000 users share an IP:

User Type	Percentage
Regular browsing	95%+
Shopping	High
Social media	High
Your proxy traffic	Tiny fraction

Your requests blend into legitimate traffic.

2. Blocking Is Risky

Websites choose to allow mobile IPs rather than block paying customers.

3. No Static Fingerprint

Unlike datacenter IPs:

• Mobile IPs change frequently
• Same IP serves different users over time
• No consistent "proxy signature"

CGNAT vs Regular NAT

Feature	Home NAT	Carrier CGNAT
Scale	1 household	Thousands of users
IP assignment	1 public IP per home	1 public IP per many users
Port range	Full range	Subset per user
IP reputation	Can be flagged	Too risky to flag

IP Assignment Behavior

When You Get a New IP

Factors Affecting IP Assignment

Factor	Effect
Time of day	Peak hours = faster IP reuse
Location	Different towers, different pools
Carrier	Each has own IP allocation
Session length	Longer sessions may keep IP

Practical Implications

For Web Scraping

Advantage

Mobile IPs rarely get blocked even with high request volumes, because blocking would affect real users.

For Account Management

Advantage

Social platforms see mobile IPs as "normal user" traffic, reducing verification triggers.

For Ad Verification

Advantage

Ads served to mobile IPs represent real mobile user experience.

CGNAT Limitations

Limitation	Impact
Can't host servers	No incoming connections
P2P challenges	Some protocols don't work
Gaming latency	Extra NAT hop
IP tracking difficult	Hard to identify individuals

For Proxies

The "can't host servers" limitation is solved by Proxidize's Cloud Router, which creates an outbound tunnel.

Identifying CGNAT IPs

CGNAT typically uses these private ranges:

Range	Type
100.64.0.0/10	Official CGNAT range (RFC 6598)
10.0.0.0/8	Private, often used by carriers
172.16.0.0/12	Private range

When your phone shows an IP in these ranges, you're behind CGNAT.

See Also

• How Mobile Proxies Work - Complete proxy overview
• Proxidize Architecture - How Proxidize leverages CGNAT