NAT64

Summary

DirectAccess can be configured to allow clients to connect to IPv4-only resources on the intranet by using the integrated NAT64 and DNS64 functionality on the RemoteAccess Server. DirectAccess requires end-to-end IPv6 communication between DirectAccess clients and the internal resources that they connect to on the intranet. Many resources are not directly accessible over IPv6, including computers that are not capable of running IPv6, or computers with services that are not IPv6-aware (for example, a server that only supports IPv4, or a Windows 2003 server which is IPv6-capable but has services that are not IPv6-aware). When you need to connect to IPv4-only resources on your intranet, you can use the integrated NAT64 and DNS64 functionality on the RemoteAccess server. NAT64 takes IPv6 traffic on one side and converts it into IPv4 traffic on the other side. The address conversion and conversation handling operate in a similar way to a traditional IPv4 NAT device. On the DirectAccess server, NAT64 is used in combination with DNS64. DNS64 intercepts DNS queries and modifies the replies, so that requests for the name of a computer have their IPv4 address answers converted into the appropriate IPv6 address answers that direct clients to the IPv6 address for the computer on the NAT64.