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Remote desktop behind CGNAT: reaching your home computer

Remote desktop to your home computer works on your own Wi-Fi, but times out from work or on mobile data. If your ISP uses CGNAT, the connection from outside never reaches your house.

Why CGNAT gets in the way

Connecting to your home computer from outside means opening a connection into your network, usually through a port forwarded on your router. Behind CGNAT, your router doesn't hold a public IPv4 address, so the connection stops at the ISP's NAT unless the ISP opens the port (RFC 6269, section 5.2.1).

What works and what doesn't

Remote desktop between computers on your home network: unaffected.
Your home computer connecting out to other machines: that's outgoing, so it works.
Connecting into your home computer from outside over IPv4: blocked, unless your ISP gives you a public IPv4.
Connecting over IPv6: can work if your ISP gives you IPv6, the network you're on has IPv6 too, and your router's IPv6 firewall allows it.

Check whether you're behind CGNAT

Compare your router's WAN address with your public IP using the CGNAT checker or the step-by-step guide. A WAN address between 100.64.0.0 and 100.127.255.255 is the CGNAT range (100.64.0.0/10 explained). If the two addresses match, CGNAT isn't your problem; check the port forward and any inbound port blocks your ISP lists.

What to ask your ISP

"Can you move my line off CGNAT and give me my own public IPv4?" Some ISPs do this for free on request; others only with a paid static IP.
"Do you sell a static IP on residential plans, and what does it cost?" Some ISPs only sell it on business plans.
"Is IPv6 available on my line, and is it turned on?" IPv6 doesn't go through the CGNAT, but the other side needs IPv6 too.
"Will my public IP stay the same?" If the address changes, saved connections stop working. A static IP stays put.

If you do open a remote desktop port, use a strong password and keep the computer updated, since open ports get scanned by others on the internet.

Which ISPs make this easier

Of the 41 ISPs we track, 12 give home customers a public IPv4 by default, 3 offer a free CGNAT opt-out and 8 sell a static IP on home plans, per our sources. See ISPs without CGNAT, ISPs that use CGNAT, or filter the ISPs without CGNAT that sell a static IP on home plans in your state. Each ISP page also quotes what the terms say about running servers at home.

FAQ

Why can't I connect to my home computer from outside?

If your ISP uses CGNAT, your router doesn't have its own public IPv4 address. Incoming connections stop at the ISP's NAT, so forwarding a port on your router isn't enough.

Does remote desktop work inside my home behind CGNAT?

Yes. CGNAT only affects connections that come in from the internet, not traffic between devices on your home network.

What should I ask my ISP?

Ask whether it can move your line off CGNAT to a public IPv4, whether it sells a static IP on home plans, and whether IPv6 is available and turned on.

This site sticks to ISP facts. It doesn't review or recommend third-party products or services.