Hacker News new | ask | show | jobs
by Arnavion 1426 days ago
I experimented with an IPv6-only home network some time ago. It's worth remembering that DNS64 + NAT64 only help you connect to IPv4-only hosts that you resolved through DNS. Anything that gets its IPs another way, say a BitTorrent client that gets peer IPs from trackers / DHT, or something that insists on using DNS-over-HTTPS to some other unforgeable DNS server, will be unable to connect to v4 IPs.

That said, it's not clear if these VMs have outbound NAT for IPv4 or not. If they do, then what I wrote above won't be a problem.

4 comments

Hey!

Founder here, yep you're totally right, BitTorrent and this kind of application won't work as there's no outbound NAT. It's on the todo list however.

Bu pretty much everything else works just fine, e.g. hosting docker containers, Webservers, databases..

Cheers Ian

>It's on the todo list however

I'm curious, how would you support this usecase?

I'm no datacenter host but NAT64 solutions exist (and have existed for a long time, actually). More recently, 464XLAT seems to be actively implemented, fixing many of the shortcomings of individual workarounds.

Your server won't be reachable over IPv4 from the outside, but it'll work to access most IPv4 exclusive services.

Alternatively, simple carrier grade NAT, possibly using 4over6, can also work. You would provide servers with an internal IPv4 address that would get NAT'ed just like on residential homes.

You can run this on linux to get ipv4 on all types of connections: https://github.com/toreanderson/clatd

Most other OSes like Windows also have a built in CLAT implementation that works similarly.

I did notice that about half of the connections on a regular bittorrent session seems to be IPv6, so I'd expect it to work fine, although perhaps a bit slower since there are less hosts you can connect to.
Another thing to consider is that if you're torrenting you might already be going through a VPN so if you can get a v6 address to tunnel through you can get v4 traffic going through the VPN interface that way. I use WireGuard forwarding with v6-only boxes (they don't torrent, though)