How to connect ipv6 through DHCP via WIFI android?

Question

I need to connect ipv6 through WIFI.

But below code works without turning on WIFI. Let me know how to get ipv6 by turning on WIFI. I am bit confused and can you please guide me.

 public String getLocalIpV6() {
        try {
            for (Enumeration<NetworkInterface> en = NetworkInterface
                    .getNetworkInterfaces(); en.hasMoreElements(); ) {
                NetworkInterface intf = en.nextElement();
                for (Enumeration<InetAddress> enumIpAddr = intf
                        .getInetAddresses(); enumIpAddr.hasMoreElements(); ) {
                    InetAddress inetAddress = enumIpAddr.nextElement();
                    System.out.println("ip1--:" + inetAddress);
                    System.out.println("ip2--:" + inetAddress.getHostAddress());
                    if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet6Address) {
                        String ipaddress = inetAddress.getHostAddress().toString();
                        return ipaddress;
                    }


                }
            }
        } catch (Exception ex) {
            Log.e("IP Address", ex.toString());
        }
        return null;
    }