Could this be a Mountain Lion problem?

[lugesm]

I have a 27" iMac connected to my Airport Extreme through
an Ethernet cable. I am running up-to-date Mountain Lion.

Whenever I leave my iMac for a while, and it goes into sleep mode, it recovers as soon as I touch the trackpad.
However, I am no longer connected to the Internet, and nothing seems to work except a restart.

When I get disconnected that way, I can enable WiFi on the iMac and connect to the Internet without restarting the computer, but the Ethernet connection does not recover until I restart the machine.

I did not experience this Ethernet disconnect problem until I updated to the new OS.
Does this sound like a Mountain Lion problem?

Any suggestions ?

 

[d3b]

I have the same problem

Software version 10.8.1 anytime that I allow my 24" iMac to sleep the ethernet is disconnected and the only way back is a reboot !

 

[lugesm]

Update

After a lot of investigation I found the following:
1. After "sleep" the iMac running Mountain Lion WILL connect to the Internet . . . after about 15 to 25 second delay. This seems consistent. When I wrote the above post I had always given up after about 10 seconds.
2. Having written the above, this is not the way it is supposed to work. This 15 to 25 second delay is unexplainable.
3. I have contacted Apple Support twice (two different techs) and they don't have a clue.
4. I have a MacBook Air running Mountain Lion over WiFi and it never experiences this delay.

 

[Macman45]

It's known, mine takes a few seconds to pick up the connection again, and it's Ethernet cabled

 

[ire]

Same problem-solved

I had the same problem, lost connection to network and could not start any programs. Was going to do a clean install of ML. Read a post on a forum that some had problems waking hardisk after sleep mode, so I opened system settings-power settings and removed the option for letting the hardisk go to sleep. Now all may problems are gone, the screen goes to sleep but when I wake up the iMac everything works.