WiFi disaster after Lion 10.7.3 upgrade

Question

After Lion Desktop Combo Update 10.7.3 the WiFi Airport connection went down: an exclamation comma on the grey sign.
No InterNet, no WiFi.
After 3 foolish days of work, thanks also to this Forum tips&Trics, this is my walk-around:
1. Lion 10.7.3 makes a seriuos jam of the WiFi Airport settings of your iMac, producing a devious IP address who excludes your computer from any connection: very, very skiddish, indeed;
2. You must set MANUALLY your WiFi connection. Fro Your convenience I suggest to activate Airport Utillity 6.0 and after the System Settings, so You will be have a sound case-control of Your steps in real time;
3. On TCP/Ip sectio: Set IPv4, set the mask AT THE ADDRESS OF THE MODEM, set IP address of the router.
4. On DNS set the DNS address to that of the mai router.
Apply.
Turn Off the AIrport. Wait 10sec. Restar ARport and selection the right network.
Take a look with the Airport Utility (we must wait patiently, if all goes well the lights will turn from orange to green in nearly 30sec).
If all is gone well, You are on line anew.
But, Apple Inc. all of this is very disappointing.
Skiddish, very skiddish!
Best regards !

Answer 1

It sounds like your issue is with your ISP's DNS settings. Please study CNET's DNS Article and MacWorld's DNS Troubleshooting and finally change your DNS settings to:
1. System preferences
2. Network
3. Click Advanced
4. Click DNS tab
5. Click + sign
6. Add 208.67.222.222
7. Click + sign
8. Add 208.67.220.220
9. Click OK.
10. Exit System Preferences