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How to disable IPv6 in registry?

    Question

  • I am trying to disable IPv6 in a Windows 2008 R2 server. After some searching, I get two frequent results:

    Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\TCPIP6\Parameters: 

    Create a DWORD named "DisabledComponents", and set it to "ffffffff"
    or
    set DisabledComponents to "ff"

    Can someone verify which is the correct way?

    Friday, May 21, 2010 7:59 PM

Answers

  • Although both values accomplish the same purpose in current versions of Windows, "ffffffff" is the recommended value to disable IPv6 with DisabledComponents.

    Rather than using DisabledComponents, you can test whether IPv6 is even being used with the following:

    1. On your DNS servers/domain controllers, type ipconfig at a command prompt and look at the assigned IPv6 addresses.

    2. If all of the IPv6 addresses begin with "fe80" and the DNS servers/domain controllers are not on the same subnet, then IPv6 is not being used to communicate and disabling IPv6 is not needed.

    3. Alternately, look in your DNS domains for AAAA (IPv6 address) records. If there are none, then names are not being resolved to IPv6 addresses and IPv6 is not being used to communicate.

    See the "Argument against Disabling IPv6" section of http://technet.microsoft.com/en-us/magazine/2009.07.cableguy.aspx for recommendations about leaving IPv6 enabled.

     

    • Marked as answer by SoylentRed Monday, May 24, 2010 4:42 PM
    Monday, May 24, 2010 3:28 PM

All replies

  • If you want to disable ALL IPv6 components, then the "ffffffff" string is correct.  See this KB article:  http://support.microsoft.com/kb/929852 that discusses what each of the bits means and what the impact is.

    We recommend that you DO NOT disable IPv6 though - why are you needing to turn it off?  It should not cause any problems or significant traffic if it is left on.


    Dave Bishop
    Team Lead
    Windows Server Networking Information Experience Team
    Friday, May 21, 2010 8:56 PM
  • The reason is because we are having some serious issues with DNS on our domain controllers. One of the possible solutions is to disable IPv6, because we think that the DC's are using it for some reason, when our network is IPv4 only.

    As for the registry key, I know the MS article says "fffffff", but here , here , here , and here all say it's "ff". That's why I am confused. Even on technet they say it's "ff".

     

     

    Friday, May 21, 2010 9:38 PM
  • Although both values accomplish the same purpose in current versions of Windows, "ffffffff" is the recommended value to disable IPv6 with DisabledComponents.

    Rather than using DisabledComponents, you can test whether IPv6 is even being used with the following:

    1. On your DNS servers/domain controllers, type ipconfig at a command prompt and look at the assigned IPv6 addresses.

    2. If all of the IPv6 addresses begin with "fe80" and the DNS servers/domain controllers are not on the same subnet, then IPv6 is not being used to communicate and disabling IPv6 is not needed.

    3. Alternately, look in your DNS domains for AAAA (IPv6 address) records. If there are none, then names are not being resolved to IPv6 addresses and IPv6 is not being used to communicate.

    See the "Argument against Disabling IPv6" section of http://technet.microsoft.com/en-us/magazine/2009.07.cableguy.aspx for recommendations about leaving IPv6 enabled.

     

    • Marked as answer by SoylentRed Monday, May 24, 2010 4:42 PM
    Monday, May 24, 2010 3:28 PM