Windows XP SP1 or later

Check your IPv6 configuration

In order to check that IPv6 works in your PC, run in a console window:

If the result is the following (or similar):

It means that IPv6 is installed correctly. Basically you need to be able to read "5 Received".

However, if the system does not recognize the command introduced (and/or returns any kind of error), follow the instructions in the next section.

How to install IPv6

In "My network places" select properties and on the network card click again on Properties -> Install -> Protocol -> IPv6.

You can also do it from the command line with the instruction netsh interface ipv6 install.

Now, that you have installed IPv6, follow the instructions at the top of this page to make sure that it is working correctly.

Address selection configuration

In IPv6, each interface can have multiple addresses assigned to network and tunneling interfaces intended for different purposes. For this reason, RFC3484 provides a standardized method to choose source and destination IPv6 addresses with which to attempt connections.

Indeed this RFC defines two algorithms:

1) A destination address selection algorithm to sort the list of possible destination addresses in order of preference.

2) A source address selection algorithm to choose the best source address to use with a destination address.

This is implemented by the Operating System so applications do not need to include their own address selection algorithms, reducing the development burden on IPv6-capable applications. However, the algorithm can be overridden by applications if either the source or destination address is used rather its full qualified domain name (FQDN).

In Windows XP, 2003 and Vista, to have administrative control over the precedence of the source and/or destination addresses, the local prefix policy table can be managed with the netsh command as follows:

Example

The above prefix policy table shows the following:

1) If native IPv6 is available on the host, any IPv6 destination has more precedence than any IPv4 destination:

2) If 6to4 is available on the host, any IPv6 destination has more precedence than any IPv4 destination:

3) If Teredo is available on the host, any IPv4 destination has more precedence than any IPv6 destination:

Changing the address selection precedence

If you want to change the precedence of one prefix, for example Teredo prefix over IPv4 addresses according to the above prefix policy table you should use:

C:\>netsh interface ipv6 set prefixpolicy prefix=2001::/32 precedence=15 label=5