Re: Have you ever disabled IPv6 for privacy (to prevent IP leaks)?

On Sat, 7/18/2026 12:47 PM, Maria Sophia wrote:
> Q: Have you ever disabled IPv6 for privacy (to prevent IP leaks)?
>    What are your experiences?
> 
> I disabled IPv6 too completely in an attempt to prevent privacy leaks.
> My killswitch toggle broke as a result of the resulting unpredictable routing table.
> 
> Modern Windows is now IPv6-first, even if IPv6 is never used!
> If IPv6 is completely disabled, Windows loses its fallback path and NCSI panics.
>  netsh interface ipv6 set teredo disabled
>  netsh interface ipv6 set 6to4 disabled (deprecated on my Windows 10 Pro box)
>  netsh interface ipv6 set isatap disabled (deprecated on my Windows 10 Pro box)
>  reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters" /v DisabledComponents /t REG_DWORD /d 0xFF /f
> 
> Disabling IPv6 caused my killswitch to stop working because after IPv6 was disabled:
>  a. Windows lost its fallback path
>  b. NCSI panics when the default route disappears
>  c. VPN routing becomes unstable
>  d. My killswitch toggle triggers route thrashing
> 
> Restoring IPv6 was a long sequence of steps because settings had changed
> so I won't describe the restoral process unless someone wants to know it.
> 
> Apparently the correct way to disable IPv6, for privacy, is this sequence.
> 
> 1. Modify the registry
>    reg add HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters /v DisabledComponents /t REG_DWORD /d 0x20 /f
> 2. Reset IPv4 and IPv6 stacks
>    netsh int ip reset
>    netsh int ipv6 reset
> 3. Reboot
>    shutdown /r /t 0
> 4. Verify
>    reg query HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters /v DisabledComponents
>    Should show 0x20, which... 
>    a. Disables IPv6 on all non-tunnel interfaces
>    b. Prevents IPv6 leaks
>    c. Prevents IPv6 DNS
>    d. Prevents IPv6 autoconfig
>    e. Prevents IPv6 routing
>    f. Keeps NCSI happy
>    g. Keeps Windows routing stable
>    h. And which keeps my recently modified killswitch toggle stable. :)
> 
> As far as I know, IPv6 leaks will not be possible after this because with 0x20:
>    a. IPv6 addresses will not be assigned
>    b. IPv6 DNS will not be used
>    c. IPv6 routes will not exist
>    d. IPv6 traffic cannot leak
>    e. IPv6 fallback remains internally available for NCSI
> 
> For privacy, I'm about to run that sequence above, but in case others
> are ahead of me, I'd like to ask this question before I take the leap.
> 
> Q: Have you ever disabled IPv6 for privacy (to prevent IP leaks)? 
>    What are your experiences?
> 

For the average user in this group, doing this is just asking for trouble.

Make a backup first, OK ?

*******

There's no IPV6 in the room, and I didn't have to do a thing.
And it stays that way, as long as there is no Teredo Tunneling.

https://whatismyipaddress.com/

   My IP Address is:

   IPv4: ? 123.123.123.123       # It's some working value like that

   IPv6: ? Not detected	         # Strangely, this does not work <snicker>
                                 # OS is unmodified.

  Paul