# Am I behind CGNAT?
> How to tell if a public IPv4 is shared, with notes for Jio, Airtel, BSNL, ACT, and Vi.
Carrier-grade NAT means the ISP translates many customers onto one public IPv4. Outbound browsing works. Inbound connections usually do not.

The HTML page shows the public address of the connection and an ASN heuristic. The browser check looks for a 100.64.x candidate, which is stronger evidence than the ASN alone.

Per-ISP notes: [Jio](https://ipinfo.fyi/isp/jio), [Airtel](https://ipinfo.fyi/isp/airtel), [BSNL](https://ipinfo.fyi/isp/bsnl), [ACT](https://ipinfo.fyi/isp/act), [Vi](https://ipinfo.fyi/isp/vi).

This site does not quote ISP prices. Get the charge from the ISP.
## Questions

### Am I behind CGNAT?

Compare the public IPv4 on this site with the WAN address in your router. If the router shows 100.64.x, 10.x, or another private range on the ISP side, and this site shows a different public IPv4, you are behind NAT. A mobile ASN makes that more likely. It is not a count of how many people share the address.

### Am I behind CGNAT on Jio or Airtel?

Jio mobile (AS55836) and Airtel mobile (AS45609) commonly share a public IPv4. JioFiber and Airtel broadband (AS24560) depend on the plan. Vi mobile is AS38266 and AS55410. BSNL is AS9829. ACT Fibernet is AS18209 and AS24309.

### Will a VPN fix CGNAT?

No. A VPN replaces a shared ISP address with a shared datacenter address. Ask the ISP for a public IPv4, or use IPv6, Tailscale, or a Cloudflare Tunnel for reaching your own machines.