in CakePHP 1.x Through the RequestHandler Component: RequestHandlerComponent::getClientIp(); in CakePHP 2.x RequestHandler::getClientIp() is deprecated, so you can use the CakeRequest object $this->request->clientIp(); of course you can still use the server variable $_SERVER['REMOTE_ADDR']
Tag: IP
The IP Address of the client who sent HTTP request is stored in the server variable: $_SERVER['REMOTE_ADDR'];