Posts Tagged ‘nat-pt’
IPv6 NAT-PT is to be used with IPv4 to IPv6 migration scenarios and it’s purpose is to provide bi-directional connectivity between IPv4 and IPv6 domains. Cisco points out that many other transition techniques are possible, and NAT-PT (Network Address Translation – Protocol Translation) should not be used when other, more “native” options exist, such as having dual stack hosts communicate directly through dual stack routers. Another example provided of when NAT-PT is not needed is when two islands of IPv6 want to communicate over an IPv4-only backbone. We know that many different tunnels exist for this purpose. For more information about these tunnel techniques, see the Transition Technique series in this blog category.
For the job of NAT-PT, a dual-stack router with interfaces in both IPv4 and IPv6 networks is capable of performing this task. The difference from classic IPv4 NAT is that translations should be done both ways: IPv6 packets routed towards IPv4 hosts should have their src/dst addresses changed to some IPv4 equivalents and vice versa, while IPv4 packets sent toward IPv6 hosts should get both src and dst addresses replaced with IPv6 addresses.