Resolved: Browsers cannot connect to the web

[davidlv]

Macbook Air 2012 Mail works fine on WiFi or ethernet, but browsers cannot connect. What could be the possible cause? The internet system prefs pane says it is connected and has an assigned IP address.
Running 10.9.2 and Safari was working fine a few days ago, suddenly stopped. Tried a reset in Safari, no change. Google Chrome doesn't work either, got me stumped. It is not my machine, but owned by a good friend, who is not very tech minded. Any ideas appreciated.
Resolved; deleting the files noted below in the HD/Library/Preferences/SystemConfig folder immediately cleared the problem.
I also ran Disk Warrior on the target SSD (lots of red ink!) and Onyx to clear off some of the built up junk.
Pretty speedy laptop now, 11" MacBook Air!

 

[satcomer]

Did you check your DNS? To check open System Preferences->Network pane, Advanced button, DNS.

 

[Sital]

Easiest first thing to try is rebooting the computer and router/modem.

 

[davidlv]

Did you check your DNS? To check open System Preferences->Network pane, Advanced button, DNS.

Yes, tried that, used Google's DNS, no change - still no browser works.
Updated the OS to 10.9.2, again no improvement.
Rebooted, used the Command + s key boot ran fsck -fy, no problems found with the 128GB SSD.
Will try a safe boot, shift key down at boot, next.
I want to try deleting the various caches, but with no browser, will have to wait a few days to get Onyx installed, the laptop is being used by the owner, a dietician and Prof. at a university, so we have to work around his busy schedule. His work requires constant browser use, references at the pubmed website, etc.
We cannot reboot the router at the university, but the situation is the same even when connected by the Apple USB-ethernet dongle, so obviously it is something in his preferences or caches; as I said Mail works fine so he obviously has an internet connection.
Thanks for the replies!

 

[davidlv]

Anyone know what preference file controls all browsers access?
I know the issue with no browsers working is specific to the users machine, it is not a router issue. Mail works, but no browser does.
Will try deleting caches next.

 

[TPadden]

Macbook Air 2012 Mail works fine on WiFi or ethernet, but browsers cannot connect. What could be the possible cause? .....

Anything plugged into USB 3.0 ports? Some devices and/or some cables on mine interfere with an otherwise good Wifi connection (no indication other than browsers won't connect)......... could even be the ethernet dongle on USB 3 is causing the RFI......

Known problem: http://support.apple.com/kb/ht5172#15

 

[davidlv]

Anything plugged into USB 3.0 ports? Some devices and/or some cables on mine interfere with an otherwise good Wifi connection (no indication other than browsers won't connect)......... could even be the ethernet dongle on USB 3 is causing the RFI......

Known problem: http://support.apple.com/kb/ht5172#15

Thanks for the suggestion, but that does not seem to be the cause of the issue here. No browser works even when connected to the web by ethernet. Mail works and I have an IP assigned according to the network system prefs pane.
No devices connected via USB.

 

[.X.]

Check that DNS is working by typing this in a terminal window:

ping www.google.com

and press enter.

It should resolve into an IP adress. If it doesn't, you have a DNS problem.

If that works, but you can't access www.google.com from any web browser, then you might have some kind of firewall or router problem.

In that case, try connecting the Macbook Air to another network at some other location and see if you can browse to www.google.com when connected to that network. If it still doesn't work, the problem is with the Macbook Air itself.

Good luck.

 

[davidlv]

Check that DNS is working by typing this in a terminal window:

ping www.google.com

and press enter.

It should resolve into an IP address. If it doesn't, you have a DNS problem.

If that works, but you can't access www.google.com from any web browser, then you might have some kind of firewall or router problem.

In that case, try connecting the Macbook Air to another network at some other location and see if you can browse to www.google.com when connected to that network. If it still doesn't work, the problem is with the Macbook Air itself.

Good luck.

Thanks! Will try that next Sat. when I meet my friend (diagnostics session).

 

[dastinger]

Hey guys,

Was about to open a thread with exactly the same issue and found this on the first page.

I'm a Poker player and spend most of the day on my Retina MBP playing online. Since 3 to 4 days ago, I am able to keep on playing without a single issue but Safari can't connect to the internet nor does Sparrow. If I quickly turn Wifi Off and On again, the issue is solved but it ends up happening again.

I will try pinging Google next time it happens and see if the issue is related to DNS but it's just totally weird that I am able to keep on playing but unable to browse. Also, this is totally intermittent so I can't really reproduce it when I want to.

I don't have any kind of AV installed but I do have Hands Off. All I tried with it so far was disabling all the rules but that did not help. I'll try quitting next time and see if that helps.

 

[dastinger]

Ok, right after I posted, same thing happened. Tried pinging Google and couldn't so it's probably DNS. I changed my preferred DNS servers to Google's. Let's see if that fixes it. Thanks a lot

 

[davidlv]

Ok, right after I posted, same thing happened. Tried pinging Google and couldn't so it's probably DNS. I changed my preferred DNS servers to Google's. Let's see if that fixes it. Thanks a lot

I found a post in the MacBook Air forum (cannot find it now to post it .. argh) saying that deleting the "com.apple.airport.preferences.plist" and "NetworkInterfaces.plist" in: Macintosh HD/Library/Preferences/SystemConfiguration/ , followed by an immediate reboot, will fix the issue (may come back later). Haven't had the chance to try that myself yet.
This seems particular to MacBook Air models and probably independent from the DNS issues. Google's DNS servers are not always the best, depending on your location.
Namebench (Google that for the download link) will find the optimal DNS server for your location, but that will change so probably need to run it once every few months.

 

[dastinger]

I found a post in the MacBook Air forum (cannot find it now to post it .. argh) saying that deleting the "com.apple.airport.preferences.plist" and "NetworkInterfaces.plist" in: Macintosh HD/Library/Preferences/SystemConfiguration/ , followed by an immediate reboot, will fix the issue (may come back later). Haven't had the chance to try that myself yet.
This seems particular to MacBook Air models and probably independent from the DNS issues. Google's DNS servers are not always the best, depending on your location.
Namebench (Google that for the download link) will find the optimal DNS server for your location, but that will change so probably need to run it once every few months.

Thanks a lot for the additional information.

First of all, never heard of Namebench. Just downloaded and ran it and what a pretty cool little utility. In fact, Google's servers were not the best for me and I'm now with the recommended configuration.

Tomorrow I'll know for certain if the issue resided on DNS or something else since it happened pretty much everyday since the beginning of the week or so. If it doesn't happen again, I think we found my issue. If it does happen, I'll try deleting those files even though I'm on a MBP and not MBA.

Anyway, I will report back tomorrow or Saturday. Again, thanks!

 

[dastinger]

Well, it seems that, even though I am not able to ping any website when the issue is occurring, it is not related to DNS. As stated yesterday, I changed the DNS servers and, today, same thing happened.

So, as soon as I finish today's work, I'll follow OP's advice about deleting those files and see if it happens again tomorrow. Will report back.

 

[dastinger]

Well, today same thing happened. I'm completely clueless at this point. Any more ideas?

Btw, I noticed OP marked as Resolved. Care to explain how you solved it? Was it by deleting the files?

 

[davidlv]

Well, today same thing happened. I'm completely clueless at this point. Any more ideas?

Btw, I noticed OP marked as Resolved. Care to explain how you solved it? Was it by deleting the files?

Read the original post, new info at the end.
Yes, deleting 4 files in the "Macintosh HD/Library/Preferences/SystemConfiguration/ " folder : "com.apple.airport.preferences.plist" "NetworkInterfaces.plist" "com.apple.network.eapolclient.configuration.plist" and "preferences.plist",
fixed the issue immediately. Not sure that all 4 files were involved, but I saw no issues after deleting them, followed by an immediate reboot.

 

[dastinger]

Read the original post, new info at the end.
Yes, deleting 4 files in the "Macintosh HD/Library/Preferences/SystemConfiguration/ " folder : "com.apple.airport.preferences.plist" "NetworkInterfaces.plist" "com.apple.network.eapolclient.configuration.plist" and "preferences.plist",
fixed the issue immediately. Not sure that all 4 files were involved, but I saw no issues after deleting them, followed by an immediate reboot.

Didn't see that! Thanks a lot for the info. Coincidence or not, I changed my ISP (and with that the router) and it didn't happen since. If it does happen again, I'll try deleting those 4 files. I only deleted the two you talked about in the first place.