2011 iMac 21.5". Wired network, internet drops. LAN works.

[lokiju]

I have a 2011 iMac 21.5" and this has been driving me nuts lately.

My internet will drop using the wired connection but the LAN side works 100% fine.

If I do wifi this never has happened.

I do wired for higher transfer rates inside my home to my streaming devices and I have NAT's that route from external to the static IP I've assigned to the iMac.

This hasn't always been an issue but has happened here and there at times. But lately it's been very persistent.

I've checked all my cabling. I've used line testers and verified all pairs are valid. I've reset my router to factory settings.

I have all available updates from Apple.

I cleared out all my preference files and let them recreate.

Nothing at all I've tried has resolved this issue.

The "fix" is to either reboot the iMac, pull the wired connection and then reconnect it or bounce my router.

I've had to open ssh external access to my router just so I can send a reboot command that I'm able to get back into my iMac remotely via ssh when I won't be able to gain physical access to my home environment for awhile.

I booted into recovery yesterday and ran a disk repair and permissions repair hoping that'd resolve it, but did not change the symptoms.

It's become a sizable pain in the rear.

Does anyone have any experience with this sort of issue that can help me better pin down where the issue is?

 

[boy-better-know]

No such thing as a 2011 23" iMac.

 

[Razorhog]

No such thing as a 2011 23" iMac.

While true, that statement is not helpful at all.

Sounds to me that your router might be at fault. Can you put the wire in a different port on the router? Either that or the port on the iMac might be going bad.

 

[lokiju]

No such thing as a 2011 23" iMac.

Meant 21.5"

 

[lokiju]

While true, that statement is not helpful at all.

Sounds to me that your router might be at fault. Can you put the wire in a different port on the router? Either that or the port on the iMac might be going bad.

Yes I have tried other ports and cables. The only system I have that does this is my iMac.

 

[Razorhog]

Yes I have tried other ports and cables. The only system I have that does this is my iMac.

Have you called Apple support?
Hopefully it is still under warranty. I would do a backup and then wipe it out and do a fresh install of OS X. If that solves the problem, yay. If not, take to Apple store or send to Apple for repair.

 

[lokiju]

Have you called Apple support?
Hopefully it is still under warranty. I would do a backup and then wipe it out and do a fresh install of OS X. If that solves the problem, yay. If not, take to Apple store or send to Apple for repair.

Not yet but will if I can't get it resolved.

I think I'll move it this weekend out of my office and connect directly to my router with a short cable and see if it does it still.

I have my router/cable modem in my living room media equipment cabinet and the connection that goes to my iMac goes through cabling in the walls up to my upstairs office.

I spent some time last night working on trying to pinpoint the issue and wasn't able to conclude anything other than a wired connection is the issue and the symptom is external/web dies but LAN remains up. I even ran AppleJack repair from single user mode as they instruct.

I combed through Console but couldn't find any clear issues.

I watched it drop over and over from internet/outside access.

I set it to wifi only and disabled my wired and it hasn't dropped once.

I also noticed odd things like when I set my monitor to sleep (hot corner) it comes back on within 2 or so mins as if I moved the mouse. Then once the monitor sleep timeout hits it seems to stay asleep for whatever reason. I'm using a Apple Magic Trackpad so even something like using a traditional mouse and a slight movement being detected couldn't be a factor.

I also noticed that the back top right (external back of iMac slightly above/around the optical drive area) seemed really warm for just sitting there and not doing anything but clicking through settings and trying the browser from time to time.

I opened activity monitor and nothing was consuming much CPU or RAM so I'm not sure why. There were not disc in the optical drive either.

Overall I'm pretty surprise of some of these oddball issues. My prior 2009 Mac Mini never once had an issue like this. Just ran solid until the day I sold it. I'm kind of regretting not getting the new Mini instead of the iMac at this point. I was really torn between the two but figured for the money and getting a nice built in LCD the iMac was the better choice at the time.