Open the Internet Connectivity Preferences dialog and use the Test Internet Connectivity button. Make sure that the box marked Allow Mathematica to Access the Internet is checked.
If the test fails, note how long it took. If there was a minutes-long delay, skip to "Check Your Proxy Settings" for troubleshooting information.
Mathematica's proxy settings are configured in the Internet Connectivity dialog.
By default, Mathematica will attempt to use system proxy settings, if your operating system has them, using the setting Use Proxy Settings from My System or Browser in the Proxy Settings section of the Internet Connectivity dialog (Help ► Internet Connectivity).
If you are experiencing connectivity problems, it is possible that your system has incorrect proxy information or that you do not use a proxy to access the internet. To test this, select the setting Direct Connection to the Internet.
For Windows Firefox users, proxy settings are found in Tools ► Options. Click Advanced at the top, and then click the Network tab that appears below. Click the Settings button in the Connections section, and a proxy settings window will appear.
If you are using Windows, try unchecking the Use same proxy server for all protocols checkbox in the Proxy Settings dialog under Control Panel ► Internet Options ► Connections and then clicking the Advanced button in the Proxy Settings section.
If the Test Network Connectivity button (described in "Test Internet Connectivity") fails after a minutes-long delay, an incorrect SOCKS proxy configuration is likely to be the problem. Mathematica does not require a SOCKS proxy, but will attempt to use one if the SOCKS proxy information is available.
For more information about Mathematica's connectivity capabilities, see "Internet Connectivity".
If the information in this document does not help you resolve your connectivity problems, consult the Wolfram Research Technical Support troubleshooting guide at