¿Cómo establecer la configuración DNS?

¿Usted sigue estos pasos:

Mac OS X

Configuración de DNS especificado en la ventana de la Red.

Ejemplo: Cambiar la configuración del servidor DNS en Mac OS 10.5

From the Apple menu, click System Preferences, then click Network. 
If the lock icon in the lower left-hand corner of the window is locked, click the icon to make changes, and when prompted to authenticate, enter your password.
Select the connection for which you want to configure Google Public DNS. For example:
    To change the settings for an Ethernet connection, select Built-In Ethernet, and click Advanced.
    To change the settings for a wireless connection, select WiFi, and click Advanced.
Select the DNS tab. (take note of the existing to be able to go back)
Click + to replace any listed addresses with, or add, the Google IP addresses at the top of the list:
    For IPv4: 8.8.8.8 and/or 8.8.4.4.
    For IPv6: 2001:4860:4860::8888 and/or 2001:4860:4860::8844
Click Apply and OK.
Test that your setup is working correctly; see Testing your new settings below.
Repeat the procedure for additional network connections you want to change.

Para probar que el de Google de resolución de DNS está funcionando:

From your browser, type in a hostname (such as http://www.google.com/). If it resolves correctly, bookmark the page, and try accessing the page from the bookmark. If both of these tests work, everything is working correctly. If not, go to step 2.
From your browser, type in a fixed IP address. You can use http://18.62.0.96/ (which points to the website http://www.eecs.mit.edu/) as the URL.* If this works correctly, bookmark the page, and try accessing the page from the bookmark. If these tests work (but step 1 fails), then there is a problem with your DNS configuration; check the steps above to make sure you have configured everything correctly. If these tests do not work, go to step 3.
Roll back the DNS changes you made and run the tests again. If the tests still do not work, then there is a problem with your network settings; contact your ISP or network administrator for assistance.

Posibles limitaciones:

Los Routers

Cada router utiliza una interfaz de usuario para la configuración de la configuración del servidor DNS, que son sólo un procedimiento genérico de abajo. Para obtener más información, consulte la documentación de su router.

Nota: Algunos Isp codificar sus servidores DNS en el equipo que proporcionan; si usted está usando un dispositivo de este tipo, usted no será capaz de configurarlo para utilizar Google Public DNS. En su lugar, usted puede configurar cada uno de los ordenadores conectados al router, como se describió anteriormente.