I have a MacBook Air which was working fine. Now I have awful network issues since the 10.7.3 update.
My home router is a D-Link DIR-615. I was securing the Wi-Fi network using WEP which worked great on Windows 7/XP/Vista, Ubuntu, iOS, and Mac OS X Lion.
Then I installed the 10.7.3 update on my MacBook Air and the Wi-FI stopped functioning on it. I started to receiving error messages saying, "Select a certificate and enter username and password". I googled this and decided to switch to WPA security since is more secure and though this issue would be resolved. Easily done. No more error messages, internet is working fine everywhere...except on the MacBook Air.
Now when I attempt to connect to Wi-Fi on my MacBook Air, it attempts to connect to my network and connects but gives the error message "Alert: No Internet connection". I checked and it is not getting an IP address. After two minutes or so, it receives a proper IP address, but the internet is not working. Sites simply won't load. When I try to ping my router, I get timeout messages. I have verified that my DNS settings are correct.
Here's what I've already tried:
- Turning firewall on/off/on again
- Removed Wi-Fi configuration from System Preferences > Network, and added them again
- Rebooted my router (several times)
- Installed 10.7.3 combo update
All other Wi-FI devices on my network work with no issues. It's just the MacBook Air that is having this problem.