Till recently, we used the IPv4 version which provided us with 32-bit address. But these available addresses will be exhausted soon. The newer version of IP, is the IPv6, on the other hand, offers us 128-bit addressing capability which means that there would be more number of addresses available for use and making the internet more secure (better network layer security) than the earlier version of the IPv4, with a better QoS and other features such as Mobility support, multi-casting support as well.
IPv6, the successor to the protocol currently used on the Internet, was designed in the late 1990s but has not seen deployment on a global scale. With IPv4 address space running out, the industry cannot afford to wait much longer. Now on or after World IPv6 Launch, ie beginning June 6, 2012, many websites will permanently enable IPv6 connectivity to their websites.
Most Windows users may not even notice the shift. If you have no IPv6 connectivity, then you will continue to connect as before. If you happen to have IPv6 connectivity, then your connectivity to participating websites will automatically shift over to IPv6. You can test your IPv6 connectivity here.
Force Windows to use IPv4
If you are facing issues while connecting to the Internet or certain sites, due to this reason, you can resolve your Internet connectivity issues using these Fix It’s from Microsoft.
By default, Windows prefers IPv6 over IPv4. So if you are having problems using IPv6 to connect to some websites, you can configure your Windows to prefer IPv4, instead of IPv6.
- The Prefer IPv4 over IPv6 Microsoft Fix it 50410 will configure your computer to use IP4 instead of IPv6.
- If you wish to reverse it anytime, you can use the Prefer IPv6 over IPv4 Microsoft Fix it 50441 to make your Windows go back to its defaults.
Enable or Disable IPv6 and IPv4
If for some reason, you wish to disable IPv6, it can be disabled either through the DisabledComponents registry value or through the checkbox for the Internet Protocol Version 6 (TCP/IPv6) component in the list of items on the Networking tab for the Properties of connections in the Network Connections folder viz. Control Panel\Network and Internet\Network Connections. You also have the options to Uninstall, Install or modify their Properties here.
Alternatively, you can also use the following Fix-Its from Microsoft to do the job for you. At KB929852, you will find a good number of Fix Its that will allow you to:
- Disable IPv6
- Prefer IPv4 over IPv6
- Disable IPv6 on non-tunnel interfaces
- Disable IPv6 tunnel interfaces
- Disable IPv6 on non-tunnel interfaces (except the loopback) and on IPv6 tunnel interface
- Enable IPv6
- Prefer IPv6 over IPv4
- Enable IPv6 on non-tunnel interfaces
- Enable IPv6 tunnel interfaces
- Enable IPv6 on non-tunnel interfaces and on IPv6 tunnel interfaces.
UPDATE: New finding shows the correct way to disable IPv6 on Windows systems and avoid a 5 second Boot delay. Microsoft has disclosed the correct value for the DisabledComponents registry key. See the Correct way to disable IPv6, and avoid 5 second Boot delay.
It is always a good idea to create a system restore point first before making any changes to your system.
I hope this article helps those who may be facing connectivity issues. Go here to learn more about the difference between IPv4 and IPv6.