Safari DNS problem in Yosemite? Works, then slow death...

Cybercussion, if you're getting this on multiple devices at once, it could be a router issue – something bigger than just one OS or machine. I know that among all my devices it's just my Yosemite laptop that suffers the DNS shakes, my iPhone and PC do not.

24 hours since my Applecare call and all is still working well. Apple advised me to rename the SystemConfiguration folder. After rebooting, a new SystemConfiguration folder was created automatically.

DNS lookup has now worked reliably for almost 24 hours. Normally the problem was at its worst first thing in the morning after waking up from a nights sleep but this morning, all browsers connected immediately and connection to all websites seems normal.

I also applied the same 'fix' to my Macbook Pro yesterday and it also appears to have fixed the problem on that.

I will continue to report back if there are any changes. I'm not uncrossing my fingers yet 🙂

So my working day started as usual with emails (text only) and no web browsing capabilities. So I did as you advised. I took the precaution of making screen grabs of my network settings, then created a completely new network set and then renamed the system config folder to 'SystemConfiguration-old'.

Shut down and re-boot.

Opened network settings to find all the old settings had gone and I was left with just 'automatic'. Clicked 'Apply' and it's all working.

Thank you very much, even if I have to keep re-doing this procedure, at least it works. I was starting to lose the will.

Incidentally I keep clicking the 'This helped me' stars on this forum, but whenever I re-fresh the page it's not given you a point.

Thanks again, I'll break with tradition and actually do some work this morning.

You don't need to create new network settings. Just rename the SystemConfiguration folder and a new clean connection will be created. I'm not sure what else has been lost by replacing the SystemConfiguration folder. I haven't found anything yet. However the old one is still there if I need to restore anything.

PS it's still working fine for me

I wished it was that easy. Routers set up with 8.8.8.8, and 8.8.4.4 (Google DNS). Even last night my phone refused to load a page. I checked out the Wifi info and it had the proper IP, gateway, DNS. If I hit airplane mode to reset cell and wifi it then allows me to surf again.

Other computers that are not mine work fine, including VMs like others stated.

Well, all I can say is that I am almost at the end of a second full day without any DNS hangs. This is on two macs that were both hanging every hour or so previously. One of them uses an ethernet connection, the other WiFi. My router is set to use openDNS not GoogleDNS.

I don't have an iPhone but my wife has one and two iPads all of which work fine (and always have).

I suspect that there is more than one problem at play here with different people. It seems (and I am still crossing my fingers here) that my problem was some setting in the system configuration folder which became problematic following an OS X upgrade.

Anyway, the last couple of days have been way more productive for me than I have experienced for several months.

I will continue to report as the situation develops further

Cybercussion, all I could suggest would be isolating the problem device on the network – remove all other devices and see if the problem persists. It could be interference with other devices (esp Macs) on your network.

drpeter, that's good to hear. Since the 'delete system configuration' trick did not work for my machine, I get the feeling that different folks are going to need to try as many different solutions as possible.

Day 2 after the system config rename and I was back to square one - no browsing. So I've done it again, renamed the new config folder, rebooted and I'm up and running. I might run the disk permissioins repair today just in case.

This isn't ideal, but at least I can work after the re-boot.

Beware!

This totally screwed up my macbook pro. I renamed /System/Library/SystemConfiguration to /System/Library/SystemConfiguration-old and rebooted. This caused a hang at the apple logo with the progress bar at about 40%. Even Safe boot failed. PRAM and SMC resets made no difference. I was eventually able to boot onto single user move and change the folder name back in terminal mode. Then the machine boots.

It appears the generation of a new /System/Library/SystemConfiguration is not automatic!

evanfromdayton - Oh dear! I'm sorry to hear that. This suggestion did not come from me, I was told to do it by an Applecare support representative.

After 2 days both my iMac 27" retina and my Macbook Pro are working fine and connecting to the internet normally.

It also appears to have fixed another issue on my iMac that was annoying me - namely the fact that I was having difficulty closing some windows using the red close button.

Isn't it odd that so many users are experiencing the same problem but need different fixes

evanfromdayton, that's terrible. Are you sure you deleted the right folder? I know it can get a bit confusing between /System/Library and /Library.

chownz, sorry to hear that, but I'm not surprised, as that particular fix did not work permanently for me. After re-creating all my Network Connections and VPN, I was still getting DNS timeouts.

I can state that having the DNS cache flushed every hour seems to be working for me. I haven't experienced catastrophic timeouts for 3 days now.

ric_lewis, Yes. There is no SystemConfiguration folder under /Library. Fortunately I didn't delete the folder, I just renamed it. I was able to change it back using terminal commands in bash.

The one I renamed was /Library/Preferences/SystemConfiguration.

If you renamed /System/Library/SystemConfiguration that is not the correct one and probably explains your boot failure