If you have a publicly addressable IPv4 address, why would NAT be involved? Every VPS provider I've used assigns your instance a non-RFC1918 address. That's on the host, not on a NAT device. With v6, there's no NAT.
I don't run a VPS/hosting company, so I can't say how many firewalls exist between the edge and customer equipment. I can't imagine that many even offer the service. Today's thought seems to be that's up to the server to filter traffic.
Linode offers IPv6 addresses to each instance. I'm sure there are lots of others that do, too. I can't speak for AWS; I don't work for Amazon.
> If you have a publicly addressable IPv4 address, why would NAT be involved? Every VPS provider I've used assigns your instance a non-RFC1918 address. That's on the host, not on a NAT device.
The reason for NAT in this case is that the box has one network interface, and needs to have two IP addresses - one with which it accesses the local network, and one over which public client connections come in. Unfortunately, IPv4 doesn't allow this - yet another problem solved by IPv6, which in the meanwhile is hacked around by means of NAT.
> With v6, there's no NAT.
Yes. I know. Seriously, you're preaching to the choir when it comes to how many problems IPv6 solves, and how much NAT has broken the internet. I just think you have a very rosy view of how far along IPv6 deployment is.
> Linode offers IPv6 addresses to each instance. I'm sure there are lots of others that do, too.
And that is AWESOME. Actually, in my 10 minutes of research, it seems like most of the smaller providers do (a big wave of them, including Linode, added support around 2011). My experience is with AWS and co-los, where the situation is much, much worse. Absolutely, if your provider gives you IPv6, use it. Please.
> Unfortunately, IPv4 doesn't allow [two IP addresses on one network interface]
That has nothing to do with IPv4, and has everything to do with you using obsolete tools (ifconfig). Use “/bin/ip address add $ADDRESS/$NETMASK dev $INTERFACE” and assign as many addresses as you like – the OS and drivers supports it just fine.
(Not that this should convince anyone to stay in the sinking country that is IPv4.)
I don't run a VPS/hosting company, so I can't say how many firewalls exist between the edge and customer equipment. I can't imagine that many even offer the service. Today's thought seems to be that's up to the server to filter traffic.
Linode offers IPv6 addresses to each instance. I'm sure there are lots of others that do, too. I can't speak for AWS; I don't work for Amazon.