iPhone 4, iOS 6 update, and wifi - cannot browse WWW via DNS

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iPhone 4, iOS 6 update, and wifi - cannot browse WWW via DNS

Apologies for the long post in advance. Hopefully it's exhaustive enough for Apple to take notice.

tl;dr:

updated iPhone 4 (VZW) to iOS 6 on home wi-fi. now phone will not browse to WWW on home wi-fi, EXCEPT WHEN BYPASSING DNS (ie, browsing by IP address). tried lots. no success

full events detail:

I updated my iPhone 4 to iOS 6 yesterday evening (via iTunes on my Win 7 x64 PC). Upon completion, I ran into some trouble trying to sign in with my AppleID in order to restore from my iCloud backup. Suspecting that Apple's servers were just experiencing trouble (though nothing indicated iCloud was down), I skipped signing in and went about my day. The rest of my settings copied across from my computer. At that point, I slept on it.

The following morning (today), I noticed that I still could not sign in, but was off to work and did not have time to examine it further. At the office, all seemed well, and I used the phone with the updated OS largely without issue, including connecting to two new wifi networks. Returning home, however, I noticed that the behavior was the same as the previous evening, ie I could not connect to things like the App Store in order to install updates, the web to look for information, etc. Now having time to troubleshoot, I pressed forward with the investigation and immediately found a number of support community and web threads detailing wi-fi issues on devices after updating to iOS 6. I followed the steps I found, but I still have the same issue. Below is the list of things I've attempted, to the best of my ability to recollect.

1. forget network, rejoin - same symptoms

2. power off phone, power on - same symptoms

3. set wi-fi network HTTP proxy to Auto - same symptoms

3. forget network, power off wi-fi, power off cellular data, power on wi-fi, rejoin network (same symptoms), power on cellular data (same symptoms)

4. power off bluetooth (already done, no change), power on bluetooth - same symptoms

5. forget network, airplane mode on, power on wi-fi, rejoin network - same symptoms

6. clear cookies, cache, website data - same symptoms

7. try another browser (Opera) - same symptoms

8. try static IP on wi-fi network - same symptoms

9. forget network, power off router, turn off wi-fi, power off phone, power on phone, reset network settings, power on wi-fi, power on router (after 5+ mins), rejoin - same symptoms

10. restore phone to factory defaults (same symptoms) and restore from backup (same symptoms)

11. enable SSID broadcast on router - same symptoms

12. enable WMM on 802.1n router - already enabled, same symptoms

13. disable 40MHz channels on 802.1n router - same symptoms

14. set router to 802.1g operation - same symptoms

15. remove wireless security from wi-fi network - same symptoms

16. change SSID - same symptoms

17. update router firmware - no updates available, also, same router was working prior to update and continues to work without trouble with all other wi-fi devices in the house

18. try another router - already verified this works, but as a result of the particulars of this case, is not relevant as my home router is not at fault, so much as the update to iOS 6 is on my iPhone 4. as other routers work and as a factory restore did not resolve (prior to backup restoration), I also do not believe my iPhone 4 to be at fault, so much as the software update itself

Having exhausted all of those suggestions, I dug further. The phone was working without issue up until the moment it needed to reboot to apply the downloaded iOS 6 update. I initially encountered the incorrect password scenario during the post-update configuration, but after forgetting and setting up the wireless profile from scratch (from the iOS 6 setup wizard), it joined my wi-fi network. The phone DID pull an IP address from my router, and responded to pings from other devices on my network without issue. In addition, using the Safari browser to web to a local network device, such as my router, was successful, indicating that the wi-fi network was established and routing appropriately. All other devices on the network, wired or otherwise, were working without issue. I then attempted to trace traffic and found that none of my phone's web requests were reaching my router, except for those targeted at the LAN. I then tried browsing to an IP to ensure there was not a DNS issue, and my phone browsed successfully. I then tried another site by domain name and failed, and then its IP and was successful. I verified against my router's logs that the web requests were routing through it to ensure that my cellular data wasn't taking over, and the logs confirmed it. At that point, I tried changing DNS from my standard servers to another set, but the behavior remained the same. I then tried setting my router as the DNS server, but the issue remained.

In conclusion, it appears to be some sort of DNS issue specific to the update. I would also hazard a guess that this is impacting people on the networks where they downloaded the update and/or were connected when the phone actually updated. I've tried setting the profile to use local, ISP, and public DNS servers, but as the requests never reach my router, I am inclined to believe it's being restricted by a setting on the phone itself. Because the problem persists through a factory restore, it would seem to point to all data not being truly erased during that process. Recall that I'm having the same issue prior to a backup being restored to the device, and that this issue prevents iCloud from being accessed during the setup process while on the problematic wi-fi network, so that should rule out the backup playing any part in the trouble.

Any thoughts?

iPhone 4, iOS 6, can browse LAN, can browse with IP

Posted on Sep 21, 2012 12:27 AM

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Answer 1

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macman.ryan Author

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Sep 21, 2012 6:15 AM in response to macman.ryan

tl;dr:

setting up a web proxy on my PC and pointing my iPhone to it works just fine. reverting does not.

full detail:

Just a quick update. I installed a program called Fiddler on my PC and used it to configure my home computer as a web proxy. I then set my phone's home wi-fi network to use a manual proxy and entered my computer's local address information and Fiddler's listening port.

With that set up, I can watch my phone's web traffic. Incidentally, I can see the wi-fi network successfully hit Apple's test page when turning the wi-fi on and/or joining the wireless network. I can also successfully browse, while I'm on the proxy. However, once I disable the proxy, the phone returns to being unable to browse by domain name, including to sites that Safari just successfully visited (and should likely be cached). This would seem to rule out the phone possibly having an issue due to being unable to hit Apple's test page during the initial update.

Will update more when and/or if I discover anything new.

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Answer 2

macman.ryan Author

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Sep 23, 2012 4:58 PM in response to macman.ryan

Did some more work on this. DNS requests from my iPhone DO leave my wireless bridge (a Belkin F5D8233-4v3 set up as a wireless access point) as verified by a packet capture done from a hub in between the bridge and my router. Previously, I'd only been able to monitor that traffic at my router, where the requests were not showing up in my logs.

At that point, I suspected an incompatibility between my router (Sonicwall TZ170 SP Standard) and iOS 6. To confirm, I reset the Belkin to factory defaults and connected it to my ISP directly, letting it handle both wireless and routing duties. I was able to browse without issue, seemingly confirming the issue with my router. However, I then put my Sonicwall back into place as my router, and reconfigured a Comtrend ADSL modem I still had (CT-5361t) to be in bridged mode with the same wireless settings used by my Belkin. I was able to browse without any trouble, which indicates that the Sonicwall is not the problem either. I then reinstated my Belkin and returned to the same issue.

So, I am now reduced to an apparent incompatibility with iOS 6 (maybe just on iPhone 4) when employing a Belkin FD8233-4v3 router as a wireless bridge to a Sonicwall TZ170 SP. The DNS request packets sent by the iPhone when using the Belkin and Comtrend as a wireless bridge appear to be identical, at least at first glance, though I have yet to go over them thoroughly.

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Answer 3

macman.ryan Author

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Sep 24, 2012 12:19 AM in response to macman.ryan

Today, I tried numerous backups and restores. I even downloaded an old ipsw firmware file for iPhone 4 CDMA 5.1.1 just to find out Apple is no longer signing that version (preventing shift-click restore in iTunes from working). So I was left with checking out the packet captures fully.

After further analysis, the DNS query packets were identical except for their transaction id's (normal, afaik). As a last resort, though I felt it an unlikely fix, I hard-reset the wireless AP back into a router via its factory reset button. Attaching my iPhone to it without any further configuration, it was able to get online normally. I configured the wireless to match the old network, and that was successful, as well. Finally, I put it back into wireless AP configuration, and I am still online. I will monitor for a few days, but after more than half a week of struggling, things appear to be back to normal.

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Answer 4

Sep 24, 2012 7:12 AM in response to macman.ryan

Updated my iPhone 4 to iOS 6 and cursing myself for having lost many useful functions apart from losing the ability to use my home network to view videos and TV. After update,I am able to browse and download apps but not able to use iPhone for viewing any streaming content like videos on youtube, BBC iplayer etc.,

The problem seems to be only with streaming content and only from home. When I connected from a different wifi location, I am able to use my phone as before.

I can't quite figureout what could be wrong. I tried all options like reset, restore, wifi reset etc.,

Any help will be much appreciated.

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Answer 5

Sep 24, 2012 7:19 AM in response to macman.ryan

This may help some - IOS6 seems to have issues with WPA2 keys

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Answer 6

Sep 24, 2012 9:29 AM in response to macman.ryan

I have the same issue with iPhone 4 and iPad 2. The iPhone 3 and iPhone 4 that I did not update to ios 6 are working fine.

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Answer 7

Sep 24, 2012 6:35 PM in response to macman.ryan

The OP is correct, I have done many tests. With IOS6 there appears to be a dns issue in some cases with IOS for both ipad(2) at lease (my wife won't let me upgrade here v1) and the iPhone4s in my case. Pretty easy to diagonse, I wish Apple would fix it.

1.) I use a Juniper 5GT wireless firewall and all of my other devices (many apple, ipad, MBP, iMAC,3 ipods etc) are fine: Not ipad2 or iphone4s running IOS6

2.) after upgrade nothing worked. narrowed it down by messing with dns (I have my own dns server)

3.) Strange thing; dns works over MiFI (Verizon) and Carrier

4.) confirmed that it is a dns and not network issue.

-down load free tool called ping-scope-lite. (obviously you need to turn off wifi to do this)

http://itunes.apple.com/us/app/ping-scope-lite/id431500107?mt=8

turn on wifi

- ping Level3 dns server 4.2.2.2 or Googlesdns servers 8.8.8.8 or 8.8.4.4 these worked.

-now ping by name google.com or ipchicken.com

- try others; same result.

Apple did say that they would give me another iphone 4s: I just wasn't sure that would fix my issue. I tried downgrading to 5.1.1 but I got an error saying my device wasn't able to do so (tried even blocking itunes from contacting Apple) I whis this could be fixed. I did even have it working using my own dns server but now I can see that my phone over wifi isn't even trying to make a dns request now.

Stuck

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Answer 8

Sep 24, 2012 9:59 PM in response to macman.ryan

Apple - Fix this!!!!!!

Apple, THIS IS WHERE YOU NEED TO LOOK on iOS 6 regarding "WIFI Lockout"!!!!!!

When this happens (WIFI freezes up aka "WIFI Lockout") – you can not get on internet while using WIFI!!!!!

You could be in the middle of surfing or using any app that makes data calls based on DNS and suddenly you can go no where or do nothing!

Yea sure, you can restart the WIFI connection, but WHO wants to CONTINUALLY do that?????

Apple (or any curious iOS 6 user that wants to see my point), when this happens open up a browser before you reset, disconnect/reconnect WIFI ( I tried both safari and chrome ) and type type 74.125.227.144 (google) and then “go”. A google search page will come up and you will be able to execute a search. (of course any link you click on will not work as it is dependant on DNS resolution)

Non DNS traffic works so the issue is not the WIFI connection to the access point!

APPLE, FOCUS ON FIXING THIS DNS DATA ISSUE AND YOU WILL GET MANY PEOPLE OFF YOU BACK!!!!

I KNOW THIS IS NOT ALL OF THE PROBLEMS WITH iOS 6, BUT THIS IS A HUGE PROBLEM NOT BEING ABLE TO SURF OR GET DATA THE iOS 6 DEVICE IS REQUESTING!!!!!

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Answer 9

Sep 29, 2012 10:06 PM in response to macman.ryan

I have an iphone 4 and have also just updated to iOS 6. Whenever I try to connect to a game in gameranger, using my iphone as a hotspot with 3G, it now tells me that I am "behind a firewall". I can surf the net and for some reason play Diablo 3 but just not gameranger. My wife has the same phone and has not downloaded the update. She does not get any such message. I have scheduled a phone meeting with apple support tomorrow but if anyone has any ideas I'd love to hear them.

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