Q: Installed Lion, now cannot connect to internet!!!

Nothing has worked for me and I am on the phone with apple.

Me either, I've checked the DNS settings with my ISP. I still get connected, then lose it again at random times - someone else said theirs was going when the computer went to sleep, mine is just going at any given time. And, of course, Apple support are closed for the night here.

I want Snow Leopard back.

Open Network Utility and ping a known good site for 15 minutes.

See if there are mayor hik-up's if so, its likely that you have a bad Airport card.

Congrats - you're now connected

I'm having a similar problem, but I don't get these 'probably a bad airport card' comments. Why would a hardware fault perfectly coincide with a software change for several people in the same way? It's usually something software related.

Support told me lion did a firmware update on airport so the router/modem is not recognizing it. He suggested restarting the router and see if it updates. Unfortunate I do not have access to my network router so I have to find a way to do a remote restart.

I suggested to use the network utility in order to verify the basics....

*sigh* So after everything; got the correct DNS settings, added the Google ones as a tertiary setting' I didn't just restart my router, I restarted and reset - and I've been connected continuously for a while now.

Thanks for the help Roger et al.

I have the same issue and have tried resarting all network hardware, server, added back my DNS (Why was this wiped in the first place??) and I still have no internet. Can't believe this passed muster for release like this. Nice. Anyone have any other suggestions? Thanks!

Avast got me too!.  I also edited the IVP6 settings to local link only, but not sure if that was necessary...

Still nothing? Where is a support rep for a solution? I have work to do and this blows chunks :/

Thanks swingman, I have tried manually (copied settings from another imac) and automatically. No love on either front. The really odd thing here is that when in automatic mode under Lion the assigned network IPs are off. Instead of the standard 192.168.X.X I'm getting seemingly random assigned IP such as 169.254.12.187

And that's DHCP manually and automatic BTW. Wifi and Ethernet, same story. I have restarted everything in order and turned off all computers on the network and still nothing. Have no firewall or anything like that installed that would be affecting the connection.