Can two offices communicate if one uses IPv4 and the other IPv6?

Question

If I get an IPv6 from my ISP for my new office branch, will I be able to communicate with my old branch that is using IPv4?

Answer 1

Provided that you get both, then yes. You need IPv4 to communicate with IPv4 hosts and IPv6 to communicate with IPv6 hosts.

Technically, there is "NAT-PT", NAT Protocol Translation, to let you access IPv4 stuff when you only have IPv6, but that would need to be run by the ISP and I wouldn't want to try to set up a VPN through that.

So adding IPv6 won't break IPv4 stuff. Having only IPv6 would be a problem.

Answer 2

You should be fine (there's not a lot IPv6 around yet), but it depends on the implementation in your hardware and software:

• On the operating system side: No problem, all modern operating systems are dual stack, i.e. they support both IPv4 and IPv6 and choose the proper version automatically.
• You'll probably get new hardware, i.e. an IPv6 router. It's reasonable to assume that it will be dual stack, but you might need to configure it properly.
• If all else fails, you can still fall back to a 6to4 tunnel which practically wraps your IPv6 packets in IPv4 packets.