Displaying Teredo Client Status

To verify the current state of the Teredo client on your computer, open a Command Prompt window using local administrator credentials, and then type the following command.

For a computer running Windows 7 on which Teredo is currently inactive, the typical output for this command looks like this.

Note If your command output doesn't contain all the preceding information, you probably started your command prompt session using standard credentials instead of administrator credentials.

If you now start an IPv6-enabled application that uses Teredo, such as Windows Meeting Space or Windows Remote Assistance, and then type the same Netsh command, the command output typically now looks like this.

Teredo Parameters
---------------------------------------------
Type 			: default
Server Name 		: teredo.ipv6.microsoft.com.
Client Refresh Interval : 30 seconds
Client Port 		: unspecified
State 			: qualified
Client Type 		: teredo client
Network 		: managed
NAT 			: restricted

Comparing these two command outputs shows that starting an application that uses Teredo changes the Teredo client state from Dormant (inactive) to Qualified (active).

Note The output of the netsh interface teredo show state command also tells you the type of NAT your computer is behind (if any). In the preceding example, the computer is behind a restricted NAT. Teredo works well behind restricted and cone NATs and can even work behind symmetric NATs, but communication between certain types of NATs doesn't work. If you plan to purchase a Small Office/Home Office (SOHO) router for broadband Internet connectivity, the best choice is a router that supports 6to4. For more information on how Teredo works and on the different types of NATs, see "Teredo Overview" at http://technet.microsoft.com/en-us/network/cc917486.aspx.