Ip ususario InetAddress

InetAddress address = InetAddress.getLocalHost(); 

     NetworkInterface ni = NetworkInterface.getByInetAddress(address);
	            
     byte[] mac = ni.getHardwareAddress();

Dessa forma eu pegando o ip que vem do usuario nao funciona....eu tenho que fazer alguma conversao !?

String ip = request.getRemoteAddr();
	            
	            InetAddress in = InetAddress.getByName(ip);

                   NetworkInterface ni = NetworkInterface.getByInetAddress(ip);
	            
	            byte[] mac = ni.getHardwareAddress();