[Nursie]

Carrier-grade NAT. Generally rolled out due to IPv4 exhaustion.

Under CGNAT Your router does not get an externally reachable IP address from your ISP, as it sits behind ISP-level NAT router that assigns addresses to subscribers much like your home router assigns addresses to your home machines.

So you can’t run any sort of externally reachable service at all.

[alephu5]

My ISP gives a dedicated IPv4 to anyone that asks, everyone else goes on CGNAT. Hardly anyone asks so they don't mind.

[nivenkos]

Usually the ISP will provide some sort of port forwarding though.

[olyjohn]

Like... what ISP would go out of their way to do that? Call me cynical, but I doubt there's an ISP that uses CGNAT who would forward a port to you. Like, they all do the total absolute minimum necessary to get you Internet access. Why would they bother creating some way to let you forward a port to your computer? No average person needs to do that anymore now that everything is cloud-based. I could be way wrong on this, but I just have my doubts...

[shric]

My ISP let me turn off CGNAT in my account settings (defaulted to on) and let me turn on IPv6 in my account settings (defaulted to off).

[nivenkos]

Yeah, it really depends on the ISP.

It's a shame how it's become so hard, the old internet is gone forever really.