{ networking.enableIPv6 = false;
  boot.kernel.sysctl = {
    "net.ipv6.conf.all.disable_ipv6" = 1;
    "net.ipv6.conf.default.disable_ipv6" = 1;
    "net.ipv6.conf.lo.disable_ipv6" = 1;
  };
  boot.kernelParams = [ "ipv6.disable=1" ];
}