Currently Being ModeratedSep 18, 2012 8:58 AM (in response to gthull644)
Try changing the network hardware settings from Autodetect to Manual. Set your connection details appropriately and Apply.
With the hardware set to manual I've had no loss of connection after sleep.
Currently Being ModeratedSep 28, 2012 11:43 PM (in response to gthull644)
To anybody who is experiencing internet connection not being available after waking computer the problem was solved for me by changing the security setting to "WPA/WPA2 Personal".
To check what your Security Setting is go into System Preferences / Network under Internet & Wireless. Click on "Advanced" and this will show what your Security is. If it is not as above, change security setting by highlighting your network, delete it, then re add it with the new security. ENSURE YOU KNOW YOUR INTERNET PASSWORD BEFORE DELETING EXISTING NETWORK.
Currently Being ModeratedOct 7, 2012 3:55 PM (in response to gthull644)
It's clear from this forum that the cause of loss of internet connection is different for different people. This forum originally started as a loss of ethernet connection but has more recently included loss of wifi connections as well.
I have tried every single thing suggested in this forum to try to connect via ethernet after sleep and every single thing has failed. I have deleted recommended prefs, changed to manual settings, deleted ethernet and re-added ethernet to system preferences, deleted logs and caches, altered energy savings settings, tried new ethernet cables, connected directly to the modem, switched ports on both the modem and the router, zapped the PRAM or whatever, unplugged the computer, restarted dozens of times, etc., etc., all to no avail. The loss of ethernet connection has gradually gotten worse and worse and, alas, will not connect AT ALL at this time. I have a three year old iMac with all the RAM it will hold, I use an Apple AirPort Extreme as my router and have no trouble connecting to the internet via it's WiFi. It connects first time, everytime on this iMac as do all other iPhone's, iPads, and iPods we have in the house. An old MacPro connects just fine through the same router via ethernet. As I posted previously, I had finally resolved to never sleep my mac because of this problem, but unfortunately you have to occasionally restart because of computer funkiness or software updates. In the past, I've been able to unplug/replug my ethernet cable a few times and it would finally activate it's connection, but this no longer works, even with a new ethernet cable. This problem has been going on now for two years, starting just shortly after my warranty ran out. I am so discouraged by my experience with this iMac (which I didn't really want in the first place; I'd always had MacPros over the past 20 plus years), that I was hoping Windows 8 might offer a legitimate option. I believe this problem to be hardware related in my case, since I've rulled out the modem, the router, and since it would connect by manually unplugging and replugging the ethernet cable in the past. At least I can still connect to the internet by WiFi, but, looking at this forum, who knows how much longer that will last!
Currently Being ModeratedOct 7, 2012 5:50 PM (in response to Couchcowboy)
I have a 2009 iMac (3 years old) that I use with an Apple AirPort Extreme on wired Ethernet. Close to your system. i too have had connectivity issues on wake from sleep, you may have to go back along ways in this thread to see my issues. It may even be with another Mac.
The point is I have not had this problem in a longtime and I can't tell you why. At one time I thought I understood the cause and offered a solution. At one time I thought this was a DHCP issue with the computer's lease expired but not requesting a new IP. I have my computer on a fixed address from the AirPort Extreme.
I think Apple has drooped the ball on this too. I use Windows XP and 7 at work on multiple computers and never issues like this. But I am deeply committed to OS X. Have you tried a complete clean install?
I'd be curious if the problem exists under virtualization along with Windows 7.
Good luck with whatever you do.
Currently Being ModeratedOct 8, 2012 5:05 AM (in response to Steven Kutoroff)
I have tried a complete reinstall and it did not help. Don't bother.
Currently Being ModeratedOct 8, 2012 11:28 PM (in response to craigfromwinter springs)
Hi Craig. Have you looked at my reply (hybtbhmaco) of the 28 Sep 2012 to your problem re Wifi connection. It has helped one person that has responded. Have you tried my suggestion?
Hope it helps! John
Currently Being ModeratedOct 9, 2012 2:46 AM (in response to hybtbhmaco)
John, I tried your suggestion and it didn't help at the time. However, the problem seems to have cleared itself up (for the most part) on its own. Right now when awakening my computer from sleep I have to close Mail and any open Internet browser, wait a couple of seconds and then I am back up and running. Still a minor inconvenience but way better than what it was before. Thanks, Craig
Currently Being ModeratedOct 15, 2012 8:08 AM (in response to craigfromwinter springs)
This is so weird. I just found this forum and it sounds like everyone is experince the same problem as me. I have a 2011 Imac running Mtn Lion. Everything has worked great for years, even after installing Mtn Lion. Only with in the last few weeks (I think after an Mtn Lion update) that when I wake my computer up it takes a moment to restore the (ethernet) internet connection. Any suggestions?
Currently Being ModeratedOct 16, 2012 12:05 PM (in response to Popsalopagus)
While waiting to get the motherboard changed or don't feel like having a downtime... I found a solution that works for me (power mac):
So while the computer goes to sleep, it puts the ethernet to sleep, but can't wake it up.
You can kick-start it by switching the ethernet cord to the second ethernet port. That somehow sends a new signal to the motherboard to turn on ethernet for the newly plugged in cat cable.
Currently Being ModeratedNov 7, 2012 9:16 PM (in response to gthull644)
Just wanted to chime in and say I too am having this problem. Using Lion, connect using ethernet via modem. The problem seemed to begin after the upgrade to 10.7.5. So that's a few months ago I think.
I rarely shut down my Mac. It was always at sleep at night. Then I couldn't connect to the net. Didn't get a dialogue box, the browser would just open and not fully load. After a restart, connection was back. This only happened occasionally, then more frequently, not even after being in sleep mode all that long.
I haven't tried many fixes (uplugging and replugging the modem, which didn't work), and have spent the past hour reading thru this thread. Just wanted to say I am having the same issue. I only have a printer connected. Don't use time machine or time capsule. If it persists I'll start going through the list of ideas.
Wondered if Mt Lion might clear it up, doesn't sound like it.
Some pages back, someone mentioned taking their computer in and being told it was a faulty main board, that was replaced and things were okay after that. Anyone try that?
Was hoping there was a better solution than restarting all the time, wondered if that was bad for the computer. Wondered if keeping in "no sleep" mode was also bad.
Currently Being ModeratedNov 8, 2012 9:13 PM (in response to Couchcowboy)
Couchcowboy and anyone else with ethernet issues: have you tried using an ethernet-USB adapter?
Currently Being ModeratedNov 13, 2012 2:49 PM (in response to DartmouthDude)
Update: Received my ethernet-USB adapter (Monoprice USB 2.0 LAN) and it connects perfectly well after waking from sleep. Try it out if you're having ethernet issues. It's a cheap fix.
Currently Being ModeratedNov 21, 2012 8:48 AM (in response to gthull644)
I have nearly the same issue with my iMac 27, 3.4 GHz i7, since I updated to Mountain Lion.
It happens not every time the Mac comes back from sleep, but 3 or 4 times a week it will. The Ethernet connection shows up (green), I can ping my own address, but not routing to other devices is working.
What I have found out are a few things:
1. a restart will work every time
2. going to sleep again and wake up will never work
3. disable the ethernet adapter in system settings and enable it again will work every time
Solution 3 is faster than a restart but is annoying because one want to work when waking up the iMac. So I tried a little apple script for that I found at http://www.mactipper.com/2009/04/change-ethernet-status-with-keyboard.html. This works perfectly and fast: click two times and your connection is up again.
I don't know if this will work for all of you, but it helped me.
Currently Being ModeratedNov 25, 2012 10:48 AM (in response to gthull644)
I have an iMac less than 2 years old, Airport Extreme, and an ethernet hookup to the iMac. Atfer upgrading to Mountain Lion, the iMac was slow to come out of sleep (including different periods of sleep), and it took 10-15 seconds for the internet (from Comcast) to come on. I tried several suggestions noted previously, and what finally worked was downloading/using Firefox. Now, my computer wakes up fast, and the internet is ready to go thru Firefox. I can only conclude, not being a computer genius, it had something to do with Safari. Hopefully, Apple will figure this out before they lose more of their Safari customer base to other browsers (assuming, of course, that the problem lies with Safari).
Currently Being ModeratedNov 25, 2012 10:52 AM (in response to gthull644)
...and, I might add, I don't have the problem under discussion with my less-than-one-year-old MacBook Air (on the WIFi).