Internet Protocol Version 6, Teredo, and Related Technologies in Windows Vista

In This Section

Overview of IPv6 Implementation in Windows Vista

Additional References for IPv6 in Windows Vista

Additional References for the IPv6 Protocol

Section Summary

This section provides a brief overview of how Internet Protocol Version 6 (IPv6) is implemented in Windows Vista and provides a series of links to other documentation about IPv6 and Windows Vista. This section also provides brief information about Teredo. Teredo is a transition technology that makes it possible for a computer behind a network address translation (NAT) device to use IPv6 to communicate with other computers that use IPv6.

It is beyond the scope of this document to fully describe IPv6 or how it affects communication across the Internet from a computer running Windows Vista.

Overview of IPv6 and Teredo Implementation in Windows Vista

In Windows Vista, IPv6 is fully implemented, and IPv4 is also still supported. The IPv6 protocol is installed and enabled by default, and can be configured through Control Panel (in the Network and Sharing Center, click Manage network connections). If software on the computer uses both IPv6 and IPv4 addresses when communicating, the networking features in Windows Vista try to communicate over IPv6 first (although this is subject to applicable address selection rules defined in RFC 3484). The result is better connectivity for IPv6-enabled applications. Windows Vista also provides full Internet Protocol security (IPsec) support for IPv6 traffic.

Windows Vista also includes Teredo, a technology described in articles on the Microsoft Web site such as the article at:

https://go.microsoft.com/fwlink/?LinkId=71545

The Teredo client in Windows Vista is enabled but inactive by default. The feature becomes active if someone installs an application that needs to use Teredo, or chooses to change firewall settings to allow an application to use Teredo. When activated, the Teredo client must initially obtain information such as the type of NAT that the client is behind; to obtain this information, the client interacts with one or more Teredo servers. To determine the IPv4 addresses of Teredo servers, the client may send a DNS query to resolve the name teredo.ipv6.microsoft.com. You can prevent this DNS query by disabling or controlling Teredo in Windows Vista by using the following methods:

  • Using a Netsh command.
  • Changing a registry entry.

It is usually workable to disable Teredo, because other technologies can be used instead, for example, Intra-Site Automatic Tunnel Addressing Protocol (ISATAP).

Controlling the Teredo Client in Windows Vista

The following procedures describe three ways to control Teredo in Windows Vista:

  • Provide the Teredo client with the IPv4 address of a Teredo server by using a Netsh command. When you use this command, the Teredo client does not send a DNS query to resolve the name teredo.ipv6.microsoft.com. Instead, it stores and uses the IPv4 address that you provide.
  • Turn off Teredo by using a Netsh command.
  • Turn off Teredo by changing a registry entry.

To Provide the Teredo Client with the IPv4 Address of a Teredo Server by Using the Netsh Command

  1. To open a command prompt as an administrator, click Start, click All Programs, click Accessories, right-click Command Prompt, and click Run as administrator.
  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  3. At the command prompt, type the following lines (press ENTER after each line):
    netsh
    interface
    teredo
  4. At the netsh interface teredo command prompt, type the following (where IPv4_address is the IPv4 address of a Teredo server):
    **set state servername=**IPv4_address

Note

To see other options for set state, at the netsh interface teredo command prompt, type set state /? and then press ENTER.

To Turn Off Teredo by Using the Netsh Command in Windows Vista

  1. To open a command prompt as an administrator, click Start, click All Programs, click Accessories, right-click Command Prompt, and click Run as administrator.
  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  3. At the command prompt, type the following lines (press ENTER after each line):
    netsh
    interface
    teredo
  4. At the netsh interface teredo command prompt, type:
    set state disabled

Note

To see other options for set state, at the netsh interface teredo command prompt, type set state /? and then press ENTER.

To Turn Off Teredo by Specifying a Registry Setting in Windows Vista

  1. For best results, close all programs on the computer on which you are changing the registry setting.
  2. To open a command prompt as an administrator, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  3. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  4. Type:
    regedit
    Caution   Incorrectly editing the registry may severely damage your system. Before making changes to the registry, you should back up any valued data on the computer. You can also use the Last Known Good Configuration startup option if you encounter problems after manual changes have been applied.
  5. Navigate to:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6
  6. Right-click Parameters, click New, click DWORD, and then type the following name for the new value (type the name exactly as shown, including capitalization):
    DisabledComponents
  7. Double-click DisabledComponents, select Hexadecimal, and then in Value data, type:
    8
  8. Click OK.
  9. Restart the computer.

Additional References for IPv6 in Windows Vista

This section provides links to additional information about IPv6 in Windows Vista.

Additional References for the IPv6 Protocol

Search the Internet Engineering Task Force (IETF) Web site for information about IPv6 or related technologies, such as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) or Teredo:

http://www.ietf.org/

(Web addresses can change, so you might be unable to connect to the Web site or sites mentioned here.)