IPv6 and IPv4 Coexistence
A version of this page is also available for
4/8/2010
Due to the size of the Internet, it is not possible to migrate IPv4 addresses to IPv6 addresses in a synchronized manner. In fact, some IPv4 addresses may never change. Therefore, IPv6 and IPv4 will coexist on the Internet. IPv4 hosts and routers must be able to run without modification and still communicate with both IPv4 and IPv6 nodes.
Windows CE .NET 4.1 and later uses dual-stack architecture that has an IPv4 stack and an IPv6 stack. For more information about this architecture, see Dual Stack Architecture.
Note
If your design uses IPv6 but does not require IPv4, you should not remove the IPv4 stack. Some transition technologies, such as 6to4, require that IPv4 is present.
Also, IPv6 nodes can communicate with IPv4 nodes over an IPv4 network. Tunneling allows IPv6-enabled sites and hosts to communicate by using IPv6 over an IPv4 infrastructure, for example, the Internet. The following table shows the available tunneling mechanisms.
| Tunneling mechanism | Description |
|---|---|
6to4 |
IPv6 sites and hosts can use their 6to4 address prefix and the Internet to communicate. They do not need to obtain an IPv6 global address prefix from an Internet service provider to be able to connect to the IPv6-enabled portion of the Internet. All that is needed is a globally unique IPv4 address. 6to4 hosts use standard autoconfiguration to create 6to4 addresses. The 6to4 tunneling technique is described in RFC 3056. |
Intrasite Automatic Tunnel Addressing Protocol (ISATAP) |
An address assignment and tunneling mechanism for communication between IPv6/IPv4 nodes within an IPv4 site. A locally administered interface, called the Interface ID, is combined with an IPv6 Unicast address prefix. The Interface ID contains an embedded IPv4 address that is used to determine the source or destination of the host. ISATAP is described in the Internet draft titled "Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)" (draft-ietf-ngtrans-isatap-00.txt). |
For more about the 6to4 tunneling mechanism, see Unicast IPv6 Addresses.
For more information about both tunneling mechanisms, see IPv6 Traffic Between Nodes in Different Sites Across the Internet (6to4).