View Full Version : IPv4 vs IPv6

08-14-2011, 09:02 PM
Does anyone have any practical experience on the differences between "IPv4-only" and mixed networks?

I'm trying to understand exactly what an "IPv4-only" network is? I can understand why individual computers might be IPv4 only. I can understand how routers and switches might be IPv4 only. But the network itself is just raw ethernet - no IP limits at that level.

I can't quite understand why the IPv6 SDK will work in a mixed IPv4/v6 "network" but not in an IPv4-only "network".

If I don't get it, I don't expect my customers to get it either.

What exactly is going to fail if they use my application built against the IPv6 SDK on an IPv4 network?

This is a real concern because I currently have four distinct products that I have to ship 32 and 64-bit versions of - making 8 deliverables. If I now have to double that up to 16 to cope with IPv4 vs IPv6, its becomes unmanageable, and I know customers will try to install the wrong thing, and blame me.

Our base-line hardware these days is Windows 7 for clients, which I understand to mean that they have a IPv4/IPv6 stack available, though not necessarily enabled. Does this count as an IPv4-only machine if the IPv6 is disabled? Does the presence of one of these machines immediately make the entire network IPv4-only?

Can anyone shed any light for me?