upgraded to mountain lion and wifi keeps dropping

I actually just made some progress...

I had previously added a syslog server on my network in an attempt to capture what might be happening when my network was dropping.

I hadnt had much luck pin-pointing anything of interest until today. I found this happening right when all my devices were losing connecting to my network -

It appears that the required DFS controls for these upper channels (in UK at least) are controlling things on their own (as designed to).

I have turned my 5Ghz network to a fixed lower channel so I shouldn't get these network drops.

If you don't hear from me, all went well!

Spoke with Apple Care who fixed my intermittent network connection issues after having upgraded to Mountain Lion:

This is what he asked me to do:

1. Go to your Macintosh HD drive in Finder (system drive)

2. Go to Library

3. Drag the 'SystemConfiguration' Folder onto the Desktop (creates a BU copy - just in case)

4. Delete the 'System Configuration' Folder within the 'Library Folder' (empty the Trash Bin - just in case)

5. Reboot - This recreates the network files (automatically)

6. That's it!

Works now like a charm

P.S.: Just in case if you have done custom network configurations, write them down first.

PPS: I did the above and it works, but please don't hold me liable for anything you do on your own machine : )

Spoke with Apple Care who fixed my intermittent network connection issues after having upgraded to Mountain Lion:

This is what he asked me to do:

1. Go to your Macintosh HD drive in Finder (system drive)

2. Go to Library

3. Drag the 'SystemConfiguration' Folder onto the Desktop (creates a BU copy - just in case)

4. Delete the 'System Configuration' Folder within the 'Library Folder' (empty the Trash Bin - just in case)

5. Reboot - This recreates the network files (automatically)

6. That's it!

Works now like a charm

P.S.: Just in case if you have done custom network configurations, write them down first.

PPS: I did the above and it works, but please don't hold me liable for anything you do on your own machine : )

I'm fairly sure you will find that the problem returns after a few days. This is definitely a router/hub security issue. The only way to get rid of this problem for good is to change your router/hub settings to WPA or WPA2. That's what myself and many others eventually had to do and my machine has been perfect ever since.

Unfortunately, if you have older devices in your home that are not WPA compatible they will no longer be able to connect wirelessly to the internet. This is a huge drawback and is a shambles. Apple need a good kicking for this.

OK how about this, I think it ties in with some of the other comments above. I started having this problem the day after Virgin Media installed my new router to take me from 20 to 60mb. My old router was set to WEP encryption and the new router is WPA2. The problem manifests itself by dropping off the Mac version of MSN Messenger Version 8. I have also tried it with Trillian and the same happens. While testing Trillian I had my Lenovo Win 7 machine running Windows Live Messenger and that stayed connected. The disconnect happens randomly but usually goes for a couple of hours before dropping out. I am wondering if it is a problem associated with WPA2 and am thinking of taking the new router back to WEP to see what happens. Anyone got any ideas about this before I go ahead with the change? (I have 7 devises attached to the router unfortunately)

I have also tried the System Configuration file tip from aboutface above. It didn't work. I just got a message saying "Wifi: No Hardware Installed" and it did not regenerate the System Configuration so not sure what happened there.

I am really hacked off with Apple. Had nothing but trouble with this machine since I bought it 6 weeks ago.... not impressed at all....

I honestly think the only sure way of curing this problem is to completely remove all internet settings, change router to WPA or WPA2 and then start again from scratch. That is the only way my system could be cured.

You are absolutely right! My old router would not convert to WPA, it only did WEP. So I bought a new router lastnight and it automatically set to WPA2 Personal. I have not had a single problem since. No more disconnections. My iMac is working flawlessly.

***For everyone else reading this, I am not recommending that you go out and buy a new router, I am just saying it worked for me because my router was old. But check your routers to see if it can be set to WPA or WPA2. You will save yourself a lot of time and money. Otherwise you may have to go to your local Apple Store or Best Buy and purchase the Airport Express or something similar.***

I upgrated my MacBook Pro from 10.6.8 to Mountain Lion 3 days ago, and noticed this wifi dropping-reconnect issue right away, about every 30 minutes or so. I have a new router (Motorola brand) and setting is WPA2 Personal. I tried every thing mentioned all above, also tried every thing googled, but still have this issue. Finally yesterday night, I spent 2 hours to use my 10.6.x installation CD to bring my Mac back to 10.6.8 from timemachine back up which I made just before Mountain Lion upgrating... I'm back to old happy time now🙂 To me, Mountain Lion is nice except this wifi dropping thing, but not impressed...

How many devices can your router hold?

The router is 'Motorola SBG6580 DOCSIS 3.0 Wireless Cable Modem'

2 iphone, 2 MacBook Pro 17 (10.6.8), 2 Lenovo T410 (Win XP, Win 7), 1 Sony TV connect to the router through WiFi.

2 Voice over IP phone connect to it through network cable directly.

All devices are happy:-)

When upgraded one MacBook Pro from 10.6.8 to Mountain Lion, it got WiFi dropping problem right away, but at meantime other MacBook Pro 10.6.8 has no problem. I'm waiting for Apple to fix that bug, I assume it is Mountain Lion bug as 10.6.x never has such problem, for Mountain Lion, after then I will try it again.

BTW, one googled thing I didn't try: Force router to stay on Wireless-G only. Most new router will handle Wireless-A/B/G/N automatically (Manufacture's default setting). But someothers said they tested and found Mountain Lion WiFi driver is a little bit too sensitive to Wireless-N somehow. They set router to Wireless-G only, then the problem resolved... I don't know if that is true or not as I forgot to try that before rollbacked my Mac to 10.6.8. Right now I just don't want to spend another 3 hours, in case it is not true for my Mac, to test it out. But if someone has the issue now, then just give it a try and let me know the outcome...

Yes, it does work - it has solved all my wifi issues.

Selection on the router's WLAN page should be set to 802.11G ONLY and nothing else.

My connection speed is strong and it feels like the internet again.....

thank for leting me know! I'm going to try the same as you did🙂 But I still have one concern: I had a 7 years old Linksys Wireless-G DOCSIS 1.0 router before. 8 months ago, Camcast infomed me that I didn't get what I paid $ for due to my router is too old, which only locked 1 upload channel (1 M) and 1 download channel (5 M) and 54 M for WiFi. So, I bought new router Motorola SBG6580 DOCSIS 3.0, which locked 3 upload channel (3.29 M) and 6 download channel (25 M), also WiFi can be up to 300 M if Wireless-N enabled (i.e. set to auto, instead of 802.11x). If set it to 802.11G, WiFi will be 54 M. If up-down load rate is 1-5 M, then WiFi 54 M should be good enough. But if up-down load rate is 3-25 M, then is this WiFi 54 M going to be a problem for router's performace? What is your router's up-down load rate?

Hi,

I also struggled with this as soon as I had upgraded to ML ... I had also the next day bought a new Router as I was having problems with the old one - but the new router also gave me the same wireless issues.

Apple has updated the firmware of my mac, which I updated... but this then made me not "see" my router at all... untill I changed the settings in the D-Link DSL-2750U ... In the Advanced - Security Settings, at the bottom ...

Wireless Security Mode - WPA2 Only (selected from drop down)

WPA/WAPI Encryption - TKIP+AES (changed - this was selected on AES)

Hope this helps/works for others!!

Otherwise I am still on the N settings, and everything else is factory settings.

Cheers,

Brad