IPv6 Support in Microsoft Products and Services (table):
Microsoft is recommending to keep IPv6 enabled. You can read more about it in this article, which I highly suggest reading it:
The Cable Guy – Support for IPv6 in Windows Server 2008 R2 and Windows 7, by Joseph Davies, Microsoft, Inc.
Basically, Joseph Davies in the above article, said (quoted directly from the article):
The Argument against Disabling IPv6
It is unfortunate that some organizations disable IPv6 on their computers running Windows Vista or Windows Server 2008, where it is installed and enabled by default. Many disable IPv6-based on the assumption that they are not running any applications or services that use it. Others might disable it because of a misperception that having both IPv4 and IPv6 enabled effectively doubles their DNS and Web traffic. This is not true.
From Microsoft’s perspective, IPv6 is a mandatory part of the Windows operating system and it is enabled and included in standard Windows service and application testing during the operating system development process. Because Windows was designed specifically with IPv6 present, Microsoft does not perform any testing to determine the effects of disabling IPv6. If IPv6 is disabled on Windows Vista, Windows Server 2008, or later versions, some components will not function. Moreover, applications that you might not think are using IPv6—such as Remote Assistance, HomeGroup, DirectAccess, and Windows Mail—could be.
Therefore, Microsoft recommends that you leave IPv6 enabled, even if you do not have an IPv6-enabled network, either native or tunneled. By leaving IPv6 enabled, you do not disable IPv6-only applications and services (for example, HomeGroup in Windows 7 and DirectAccess in Windows 7 and Windows Server 2008 R2 are IPv6-only) and your hosts can take advantage of IPv6-enhanced connectivity.
Also another impact if IPv6 is disabled (UDP 389 is seen not responding): http://tenof11.blogspot.fr/2013/08/disabling-ipv6-causes-389udp-to-fail-on.html
How do I repair TCP/IP Stack in Windows 7, Vista, or XP?
select “Run as Administrator” to open a command prompt. In the command prompt window that opens, type type the following commands, each followed by the Enter key:
- Reset WINSOCK entries to installation defaults: netsh winsock reset catalog
- Reset IPv4 TCP/IP stack to installation defaults. netsh int ipv4 reset reset.log
- Reset IPv6 TCP/IP stack to installation defaults. netsh int ipv6 reset reset.log
Reboot the machine.
For Windows XP, right click on the Command Prompt and type netsh int ip reset
Why and How do I want to turn off IPv6 ?
Get-IPv6DisabledStatus – Did someone take a shortcut when disabling IPv6?
One particularly common issue is administrators who see IPv6 bound to a network adapter and figure they can disable IPv6 by unchecking the box.
This might look promising, but you run into two issues:
- You aren’t actually disabling IPv6. You’re just saying ‘don’t use IPv6 on this particular adapter.’ Your system still thinks IPv6 is enabled.
- You shouldn’t necessarily disable IPv6. Microsoft testing of services and applications is performed without disabling IPv6…
The supported way to disable IPv6 is to use the DisabledComponents registry value.
To re-enable IPv6:
netsh interface teredo set state default
netsh interface ipv6 6to4 set state state=default undoonstop=default
netsh interface ipv6 isatap set state state=default
REG DELETE “HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters” /v “DisabledComponents” /f