I'm also planning to withdraw IPv4 (going v6-only with NAT64) because the necessary hazzle for Dual-Stack is pretty ugly.

So I'm also interested in the answer.

No it doesn't support it, Steam needs a IPv4 connection to work.

Do we know which IPs are used by Steam? I maybe have an Idea howto workaround that limitation.

https://steamhost.cn/help_steampowered_com/en/faqs/view/2EA8-4D75-DA21-31EB

So Valve has 6,476700408×10²⁴ IPv6 addresses but Steam still doesn't use IPv6?

Thats not how it work, if you own ISP use it then you need it, if they dont then its ipv4 only for you.

ps.
any issue with it talk with own ISP and they will tell you.

I have /64 ipv6 subnet on home internet connection, And /48 on my VPS. And that's A LOT! I cant' even imagine what to do with this amount of IP addresses. Valve has 31 of /48 subnets. I'm pretty sure they can run their services on every planet in our universe using ipv6

Steam needs IPv4 to work properly. The minimum you can use is Dual Stack Lite or CGNAT.

Unless laws are set in motion that ban the use of IPv4, Valve won't change anything.

Originally posted by Marzanna:

I have /64 ipv6 subnet on home internet connection, And /48 on my VPS. And that's A LOT! I cant' even imagine what to do with this amount of IP addresses. Valve has 31 of /48 subnets. I'm pretty sure they can run their services on every planet in our universe using ipv6

They can, yes. But they don't operate the entire internet. There is a lot between them and their end users. And if you've been keeping up on IPv6 deployment, it's still an uneven distribution of adoption around 50% globally. There are even some backbone nodes that are still operating on IPv4. For a service that needs to be available for everyone worldwide, they go with what works worldwide and that's still IPv4.

Originally posted by Marzanna:

Hello. I tried to use Steam on IPv6 only network (with NAT64). But It looks like Steam has no connection when I launch it. There is no problem with dual stack network. Does Steam support IPv6? It's 2024 and all major tech companies should support IPv6 for their services.

There will still be legacy games that cannot use IPv6. Software has to support IPv6 for it to be usable.

Steam's IPv4 network to the best of my knowledge supports play even on CGNAT networks where you have no ability to forward ports.

Originally posted by Marzanna:

So Valve has 6,476700408×10²⁴ IPv6 addresses but Steam still doesn't use IPv6?

Sigh, can people (in general not just you) pleas stup counting ipv6 addresses, the number of addresses is in most cases irrelevant. I understand why it's tempting to count addresses, we have be trained by IPv4 exhaustion to think about individua addresses as something precious. In IPv6 this is so far from the case it's not even funny. On most edge networks (think lan. or the natworks at your place of work) the ususal subnet size for IPv6 is a /64 ie 2^64 addresses. Will you even wand that money potential devices in a subnet, probably not. So inset of canting address count /64s, and in cases where you things are geographically distributed (like steams datacenters) and/or multihoming is used, you well need a /48 location to be able to announce the route. So unless you are only thinking about one location count /48s.

Originally posted by Crashed:

Originally posted by Marzanna:

Hello. I tried to use Steam on IPv6 only network (with NAT64). But It looks like Steam has no connection when I launch it. There is no problem with dual stack network. Does Steam support IPv6? It's 2024 and all major tech companies should support IPv6 for their services.

There will still be legacy games that cannot use IPv6. Software has to support IPv6 for it to be usable.

Steam's IPv4 network to the best of my knowledge supports play even on CGNAT networks where you have no ability to forward ports.

Hmm i wonder how that is implemented, som kind of ISP vel UPnP, nah more lightly either steam or the game developer/publisher runes some kind if relay servers so that players behind a cgnat can actually connect at all. I'll leave it up to the reader to figure out why this solution is far from optimal.

This thread was quite old before the recent post, so we're locking it to prevent confusion.