OS X Mountain Lion: If you can’t connect to the Internet
If you are having difficulties connecting to the Internet, you can use Network Diagnostics to help resolve the problem. Network Diagnostics walks you through investigating your Internet connection and tries to resolve the problem. To use Network Diagnostics, choose Apple menu > System Preferences, and then click Network. Click “Assist me,” and then click Diagnostics.
Follow the onscreen instruction in Network Diagnostics to resolve your network problems.
If Network Diagnostics doesn’t resolve your connection problems, try the following suggestions.
- Your ISP may be having problems. Wait a moment and try again. Call your ISP if you continue to have problems.
- Open the Network pane of System Preferences and check the status of your network connection services, such as Ethernet or Wi-Fi. Green indicates the service is active (turned on) and connected. Yellow indicates it’s active but not connected. Red indocates the service has not been set up.
- Compare your network settings in Network preferences with those recommended by your ISP. Make sure you’re using the latest recommended settings and that they are entered in the appropriate fields.
- If you’re using a telephone modem, try dialing your ISP’s modem number using a regular telephone to see if a modem answers and to check the line for static or other noise that might interfere with the connection. To monitor the modem as it tries to connect, turn on modem sounds. Open Network preferences and select your modem service in the list. Click Advanced, click Modem, and then select Sound: On.
- If you’re using PPPoE, do not type anything in the PPPoE Service Name field (in the PPPoE pane in the Network pane of System Preferences) unless specifically instructed to do so by your ISP.
- If you’re using Wi-Fi, search Help Center for additional Wi-Fi tips and information, or open AirPort Utility (in the Utilities folder in the Applications folder) and choose AirPort Utility Help from the Help menu.
- If you understand networking fundamentals, try using Network Utility to investigate the problem. Network Utility is in the Utilities folder in the Applications folder.