The primary design goal for network address translation was to preserve the IPv4 address space. However, it has allowed to serve for different purposes. NAT allows to operate independent network thus preventing address renumbering when the ISP is changed. The multihoming can be easily run without BGP routing and own AS number. The main drawback is, however, breaking the end-to-end connectivity. Network engineers are usually very strictly against NAT in IPv6 protocol but lack of features in IPv6 - e.g. multihoming without BGP, brought NAT even to IPv6 networks. The presentation aims to map and test current implementations of NAT and NAT66.