IPv4 has the 192.168.*.*, 172.16-31.*, and 10.*.*.* ranges; IPv6 has one range that is enormously bigger than all of those three put together, which can contain 1,329,227,995,784,915,872,903,807,060,280,344,573 devices. The standard is to use a subnet randomly chosen, to minimize conflict. This page has just generated a 64-bit subnet for you, usable for a maximum of 18,446,744,073,709,551,613 devices:
Using the above 64-bit subnet, the following is the first IP:
and this is the last:
And as with v4, you will need a subnet mask. The subnet mask for any 64-bit v6 subnet, is:
The reverse DNS zone name, for the above zone, is:
64-bit subnets are certainly usable on a LAN, but they are far larger than necessary, and smaller ones may be more manageable; please see the links below! Please note that Windows Server 2008 and 2008 R2 support only 64-bit subnets (the kind on this page) in the GUI reverse DNS setup.
If you would like to create a reverse DNS zone for the above subnet by command line in Windows Server 2008 (or 2008 R2), the following works well: