[seanlinmt]

But how do you host services through CGNAT though?

[msk-lywenn]

You can’t. When my ISP switched me to CGNAT, I spent days upgrading everything to IPv6, only to discover that gmail didn’t even support it! (Mail Server to mail server, not the web app) I gave up, asked my ISP IPv4 back and, fortunately, got back a new IPv4. But I fear the day that option will disappear…

[tambre]

What year was this? While I can't find a source I believe Gmail has supported IPv6 for sending and receiving since the World IPv6 day back in 2011. I've certainly been doing it since 2017.

Your issue might be rather that Gmail actually enforces all their guidelines on IPv6 instead of silently degrading your reputation behind the scenes like they do for IPv4. So proper RDNS, SPF and DKIM are tablestakes with DMARC and MTA-STS strongly recommended.

[msk-lywenn]

This was maybe three four years ago. That might be it. I lack rDNS but I have everything else. Except for MTA-STS, I’ll check that out

[tambre]

Yeah, rDNS is a hard requirement for IPv6. I believe you should get a hard reject for missing that with a pointer to the documentation.

[hlandau]

My mail server has been known to deliver mail to Gmail using IPv6 if I don't tell it not to. Not sure if Gmail will use IPv6 for incoming mail though.

[eru]

By and large, you don't. I suspect beagle3 cares more about the privacy aspects than hosting a service from their home.

There are some trick for hosting through CGNAT, if you have a server on the outside.

[sambazi]

either buy paying a few bucks for a vps with static v4 or try techniques like "nat hole punching" to keep the cgnat statemachine happy. but tbf it isn't meant to

[kuschku]

> but tbf it isn't meant to

Then it's not internet. Internet means there is no distinction between "servers" and "clients", everyone is a peer.

If you can't host things, you don't have internet. You've just got a modern version of MSN/BTX/Telex/whatever

[sambazi]

how it started, how it's going.

billions of ppl access the internet thru nat everyday, i'm glad it exists and also happy for alternatives

[orangeboats]

>billions of ppl access the internet thru nat everyday

A caveat is that a lot of people are knowing or unknowingly relying on things like UPnP and NAT-PMP to have services operating normally under NAT. That conveniently masked a lot of the issues with NAT in P2P usecases such as online gaming and torrenting.

Unfortunately, even that is broken under CGNAT.

The more layers of NAT you put on your connection, the more things you break.

[sambazi]

interestingly, i religiously disable upnp/pmp on all residential cpe's that i configure due to it's glaring security implications. never heard of a problem

though i do defend v4-nat internet as the way it was meant to be, being jailed behind a cgnat w/o repercussions would push me to another isp.

[orangeboats]

In gaming communities e.g. Minecraft you regularly get people asking for port forwarding related questions. Some gamedevs automate that process using UPnP, I believe Eve is one of them.

Neither solution works for me though, as someone whose IPv4 connnectivity is behind a CGNAT.

ALL ISPs in my country have deployed CGNAT so there's no "changing ISP" for me either. IPv6 is the only solution left unless I want to pay a premium to get one of those public IPv4 addresses. Really, single-layered IPv4 NAT can't last forever. The address space of IPv4 is simply too limited.