Q: iMac drops Wifi connection after 10.7.4 update

Setting the MTU to 1492 did not solv it for me.

hi all,

sorry but the change mtu operates intermittently.

is a bad idea ...

Darwin iMac 11.4.0 Darwin Kernel Version 11.4.0

While working through the issues with the Apple support rep I just happened to click on Other Airport Base Stations in the latest Airport Utility and was able to view the plethora of wireless settings my iMac was picking up, which was twelve other wireless routers. 75% of them were on Channel 6, just like mine, as that is the default channel for many routers. I switched to Channel 8, restarted my iMac, and what do you know, no more problem! In fact, my wireless throughput has gone up a lot, like 40% faster. My iMac was having trouble filtering the data coming from the exact same channels on eight other routers. I can happily state after testing this out since last Thursday that my wireless dropping issues are fixed simply by switching my Airport Express from radio channel from 6 to 8.

I obviously can't say this is the fix for everyone, but it's such a simple step it's worth giving a shot. Just make sure after you switch radio channels that you restart both router and iMac, which probably also renews the DHCP lease on your LAN and gives you a fresh connection.

And this is on 10.7.4, btw.

So far switching to Channel 8 and not Auto has worked very well for me.  Tx!

Did you check to see what other channels were currently being used by other wireless networks? Doesn't necessarily need to be channel 8, just a channel not currently being used by wireless networks around you.

My wifi is still going strong with no dropping since I made this switch, maybe you can find a channel with no one yet on it?

Sorry, I had hoped this would help folks out since it's working (knock on wood) for me.

I didn't check, and just selected 8 since it was in my head after reading your post.  So far so good....the connect used to NEVER stick overnight but this morning I was still connected. 

Out of curiousity, how do you see what channels are in use?

Hi, I cannot even find a place to change channels or to see what channels are in use. Can anybody help me? I have a 2010 iMac and am using a combo modem/dsl router. I am having wifi disconnects during both computer idle time as well as ocassionally even while I am using it. I do not have to reboot to reconnect, just go into the Network Preferences and re-sign in to my network.

Thank you.

To see which channels are in use:

Option-click on the Wifi icon in the menu bar. You'll see details about your currently selected network. For details about any other network, just hover over it:

To change channels:

You'll need to open the Airport Utility. Pick your Airport base station and choose "Edit". Switch to the "Wireless" tab and choose "Wireless Options...":

You can now set the 2.4GHz and (preferably) the 5GHz channel:

Save your changes. The base station will probably restart and you might need to re-pick your wireless network.

Hope that helps!

Jon

Thanks, but I do not get that screen when I open Airport Utility. I only get this

Both 2,4 and 5 GHz is set on Automatic on mine. Could it be like it changes to some channels sometimes that is not good for the connection. Maybe I should change to some specific channel. Any knowledge regarding this.

I have for the moment put my imac into non sleep mood and that is working so far. But of course I want it to rest sometime.

Changing to a specific channel seems to fix the problem completely. Use 5GHz mode if possible, there's far less interference on that band.

If you don't have an Airport base station, you should still be able to change the setting on your router. Usually your router will be found at http://192.168.0.1 (or similar). Search Google for information on how to configure your router.

Tried to send you a picture of what I get but I do not think it went through. I get a grey screen with a globe on it and a message that I do no thave any configured Base Stations.

I changed from automatic channel selection to manual around 4 weeks ago and I'm yet to encounter any further

problems, so I'm confident this is the best fix.

You don't have an Airport base station. You'll need to configure your router. Use your browser to navigate to your router's address (usually http://192.168.0.1 or http://10.0.0.1 or similar). You should be able to set the channels there.