Since updating to Mountain Lion I lose my internet connection every time that my 24 inch Mid 2007 awakens from sleep. It doesn't occur when going to sleep or during but only on activating it again. 100% of the time. Any ideas?
I called Apple Tech Support yesterday. My connection drops after waking from sleep, and it is a hardwired connection (not wifi). They told me it is a known problem with iMacs, and while it eventually will be fixed in a software update, the only thing to do now is to disable the machine sleep on the energy saver panel, which I did..
I had this problem too. I solved it by going to my router's configuration settings and changing some settings under the WiFi setting (it worked for me).
First of all make sure you’re using WPA2; for WPA-type use passphrase and choose your password. But make sure there are no numbers in your network password.
Second change your channel. Before I had set it on channel 6 now I changed it on channel 11.
Also make sure your encryption is set to AES.
I'm giving you also a picture of my WiFi settings down below.