Assume that we have received a block of IPv6 addresses from our ISP, and we want to map a set of local IPv6 addresses to this block. Our internal IPv6 subnet is fd30::/48. We can do the mapping with NPt:

1. Navigate to Firewall | NAT, and from there, click on the NPt tab. On the NPt page, click on one of the Add buttons.
2. On the NPt edit page, set the first Address to the local IPv6 prefix, which in this case is fd30::/48. You must enter both the prefix and the CIDR.
3. Set the second Address to the IPv6 public subnet, which is the contiguous block of addresses assigned by your ISP.
4. Click on the Save button when done, and on the NPt page, click on Apply Changes.

The mapping is complete, and it should function similarly to a 1:1 NAT mapping.