3
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?
3
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?
5
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.
1
You should be fine (there's not a lot IPv6 around yet), but it depends on the implementation in your hardware and software:
4Completely unrelated: I envy you. – Tobias Plutat – 2011-01-24T09:24:15.097