php artisan serve error

whenever I run php artisan serve, I get this.. Laravel development server started on http://localhost:8000/ [Fri Apr 15 14:45:31 2016] PHP Warning: Unknown: php_network_getaddresses: getaddrinfo failed: Name or service not known in Unknown on line 0 [Fri Apr 15 14:45:31 2016] Failed to listen on localhost:8000 (reason: php_network_getaddresses: getaddrinfo failed: Name or service not known) could you please help me on this?