How to fix No Internet Connectivity on OS X Lion

[Natalia.123]

Recently My Macbook pro is upgraded to OS X 10.7.4 LION. I have used the combo version for the installation. However after the upgrade, the system does not have internet connection. There is no way the system is going to online and not in any manner. Before the update all was fine and working great. At first I tried the network diagnostics but it didn’t work. With the upgrade of 10.7.2, it was very much fine and there was proper internet connection. The internet connection working properly in other computer but not in my Macbook pro. What do I do now?

[#4]

They were believed WiFi problems persist with the OS X Lion. The most common problem is the inability to connect to a network during the wake up of Mac, including the MacBook Air. WiFi connection appears active, but the system has not authenticated to the router, and you cannot surf. While authentication and connection are normally almost immediate, it may take tens of seconds or even disable and enable the WiFi interface to find its connection. This is sometimes not enough: some users are forced to restart their machines ... in order to connect to a WiFi network.
According to a user of Apple forums, the Keychain Access could be involved in some cases, especially if you use a password to lock your machine to sleep. If your machine is trying to connect when you type your password, it will be faced with a Keychain locked, and therefore cannot authenticate. Theoretically, disable and enable the WiFi connection once logged in can restart the process and thus connect. If you do not have a password, that user advises to remove the WiFi connection (System Preferences> Network, click Wi-Fi, then click the [-] bottom left), then recreate it. This lot of bugs will be finally settled by Apple in future updates of OS X Lion.

[Svana]

WLAN was worked perfectly on Mac OS X 10.6 Snow Leopard without any problems. Since I recently switched to a new iMac with OS X Lion, am the wireless was extremely unstable. The iMac lost with the new Apple operating system at irregular intervals, the wireless network and could not access the Internet. Outwardly, the wireless termination was not noticed - the Wi-Fi icon in the menu bar remained unchanged at full deflection, but the access was no longer on the Internet. In the short term was to provide relief by Wi-Fi disabled and then enabled again - until the next stop of the wireless connection. Oddly enough, this phenomenon has even extended to my iPad - even in this lost time to time the wireless connection.

[GracieSingh]

I assume that you have connected to the internet through the wifi connection but did you try the direct connection using the Ethernet cable or USB cable or modem something like that. Otherwise you can try More Advanced WiFi Troubleshooting steps to solve the problem. For this you have to go to the System Preferences > “Network”

• There try to set the manual IP address with DHCP in Network > Advanced > TCP/IP settings. You can choose any IP that is in the range of your router. I assume that it is obviously the problem with router most of the time.
• Move the Wifi connection name to the top of the Service Order list to simply prioritizes WiFi as the primary method
• Also move the router to the top of “Preferred Networks” list if there are multiple router’s in the same range. It may cause WiFi to drop
• Get rid of all existing WiFi connections and re-add them
• Add an extra DNS entry
• Try with New Network Location