Mac OS X: How to Disable or Enable Automatic Modem (PPP) Connections

Use these steps to enable or disable your computer's ability to automatically connect to the Internet.
To turn on or turn off automatic dial-up (PPP) Internet connections

With automatic connection disabled, Mac OS X will prompt you to connect to the Internet when necessary. You then connect using the Internet Connect application.

Additional information

Mac OS X connects to the Internet automatically in some circumstances. For example, Mac OS X attempts to connect to the Internet to:

When automatic connection is enabled and you are not yet connected to the Internet you may see a message such as "The specified server could not be found" or "A connection failure has occurred" when you open a Web browser This only means that the browser attempted to connect before the computer had completed the connection process. This does not indicate any issue with your configuration or Internet service provider. If necessary, quit and reopen the browser after the connection sequence is complete. If such messages persist after you are connected, you may need to check your DNS settings. See technical document 106798, "Mac OS: Troubleshooting 'A connection failure has occurred', 'The specified server could not be found' or Similar Messages".

If the setting to "Connect automatically when starting TCP/IP applications" is enabled in the Network pane, you may not be aware that the connection has been made. In Mac OS X versions prior to 10.1, enabling modem sound does not permit you to monitor when your modem is connecting. Updating to Mac OS X 10.1 or later resolves that issue. See technical document 106162: "Mac OS X 10.0: Internal Modem Makes No Sound When Connecting"

If you are obviously already connected to the Internet but an alert box appears with a message that says "...is not able to connect to the Internet" see technical document 106291: "Mac OS X 10.0: Software Update, Mac Help, or Sherlock 'is not able to connect to the Internet' Message"
Published Date: Feb 17, 2012