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

I'm still in touch with tech support here, because it's still an ongoing issue. They finally said it's a more widespread problem and they're working on a fix.... Which ironically will need to be downloaded. No word when that's coming, but it still wasn't ready and/or available as of yesterday.

I removed all references to wifi, Airport, Time Machine, etc., from my Keychain, as others have suggested.(There were many more than I expected.)  Then, reset the Time Machine to default and re-config'd it.   Deleted existing wifi network and created a new one.  That seems to have fixed the "no DNS after sleep" problem.  Something still blocks net access periodically during the day, though. Seems especailly notable when opening a group of tabs in Safari.  Most will just time out.

This seems to be an issue with certain apps. Firefox seems OK, but Chrome fais to load pages all the time, like Safari.  Wonder if Webkit is the common element?

Hi! For me the answer was - and remains, as I've just tried again without it and the connection dropped immediately - something I found on the OSXDaily site (http://osxdaily.com/2011/07/22/wifi-dropping-in-os-x-lion-fixes/). This is a simple and, I've found, extremely effective workaround until the problem is fixed, which it wasn't in the 10.7.1 upgrade. Give it a try!

peeyar

Another Idea: Maintaining Data Transfer

Another theory is that when data transfer stops, the wireless connection inappropriately drops. You can avoid that by simply launching the Terminal and pinging a random address, this causes a miniscule amount of data transfer to occur and that can be enough to maintain an active network connection.

• Launch Terminal (accessed at /Applications/Utilities/Terminal or by using Spotlight)
• Type “ping yahoo.com” at the command line and you will see something like this
• ping yahoo.com
64 bytes from 98.137.149.56: icmp_seq=91 ttl=52 time=27.806 ms
64 bytes from 98.137.149.56: icmp_seq=92 ttl=52 time=27.763 ms
64 bytes from 98.137.149.56: icmp_seq=91 ttl=52 time=27.806 ms
64 bytes from 98.137.149.56: icmp_seq=92 ttl=52 time=27.763 ms
• Just let that run in the background, it isn’t resource intensive

Yes. The same thing worked for me! What a relief.

Now here's a new question... Does the same probem exist in MOUNTAIN LION? (I suppose i could use the same solution...) thinking of upgrading.

Thank you and good luck.