For some reason, even if you statically assign an IPv6 address and gateway in Windows 7, it will still do SLAAC anyway and give itself a second auto generated address. Here’s how to turn that off:
- Start an administrator shell; i.e. right click Command Prompt and select the Run as Administrator… option.
- The following is all one line:
netsh interface ipv6 set interface "Local Area Connection" routerdiscovery=disabled