rgomez

Q: DNS Services using way more data than before with iOS 10?

Hello,

 

I upgraded to iOS 10 since the GM became available.

 

Some days ago I noticed a spike in my data usage on my carrier's report, and I went to check on the iPhone what was causing this. To my surprise, the culprit was DNS Services. Of the 515Mb I had consumed since the last reset (I reset it the same day as my carrier, which was on Sept 13th) 466Mb were DNS Services.

 

On the carrier's app I see that on Sept 16th there were 490Mb consumed, vs an average of 15-20Mb per day. So I assume most of those 466Mb were made that day.

 

Now, 466Mb of DNS requests are something like 5 billion requests. I was without WiFi connectivity that day for a total of maybe 90 minutes. In that time I did not use the iPhone except to hear music (60 minutes walking the dog, another 30 on the car). I can't figure out how or what made those requests.

 

I reseted the Network settings that day, and things have gone back to "normal". Except that today I can see that there are another 20Mb of DNS requests being made since the 16th. 20Mb of DNS requests are still *a lot*.

 

Has anybody else noticed an increased amount of DNS requests with the iOS 10?

 

Now, the strange part is that everything was normal before the 16th. And I installed the GM the day it came out (which was... 1 week or so before?) and I was on the betas since weeks before. I can't remember or see anything different or special being made on the 16th. Some days before, IIRC, there were some carrier updates, but why or how that would produce such an increase in DNS requests?

 

I tried talking with Apple Support, but the girl whom I was talking with just told me incorrect and illogical stuff, and got offended when I asked if she knew what a DNS request was, and closed the chat session. I am guessing I wont get any help there.

iPhone 6s, iOS 10

Posted on Sep 19, 2016 10:12 AM

Close

Q: DNS Services using way more data than before with iOS 10?

  • All replies
  • Helpful answers

  • by rgomez,

    rgomez rgomez Sep 19, 2016 11:13 AM in response to rgomez
    Level 1 (9 points)
    iPhone
    Sep 19, 2016 11:13 AM in response to rgomez

    Just for comparison: a friend's iPhone has the total of 6.1MB of DNS services for almost a year of usage. I'm sure values will be around that mark if anybody checks their info.

     

    So, is there any way to track what requests were made (by which App, or what name was being resolved) so I can try to pinpoint this?

     

    I'm in the process of restoring the iPhone, hoping that things go back to normal, but without knowing what and why this happened it's just a long shot.

  • by rgomez,

    rgomez rgomez Sep 24, 2016 8:51 AM in response to rgomez
    Level 1 (9 points)
    iPhone
    Sep 24, 2016 8:51 AM in response to rgomez

    This is still happening.  I restored the iPhone some days ago, and yesterday I installed the 10.0.2 update. After installing it, I reset the statistics and some hours later (say, 8-10) where I was with WiFi for all the time except maybe 60 mins (where I did not use the iPhone directly, just heard music or keept it in my pants) I got 13MB of DNS services of a total of 20MB of cellular usage.

  • by rgomez,

    rgomez rgomez Sep 24, 2016 8:19 PM in response to rgomez
    Level 1 (9 points)
    iPhone
    Sep 24, 2016 8:19 PM in response to rgomez

    Just checked today after coming back from the movies, and in that period (where I did not use the iPhone) I got 10MB more of DNS requests. Something is seriously wrong, but I can't figure out what.

  • by Gualberto_N,

    Gualberto_N Gualberto_N Sep 25, 2016 4:20 PM in response to rgomez
    Level 1 (4 points)
    iPhone
    Sep 25, 2016 4:20 PM in response to rgomez

    I Have the same problem, I jus updated mi iPad and my iPhone yesterday and my iPad consumed more than 2 gb in 30 min. And my iPhone more than 624 mb In 3 hours... all that from my cellular plan and the problem is DNS Services.

  • by Lawrence Finch,

    Lawrence Finch Lawrence Finch Sep 25, 2016 4:54 PM in response to rgomez
    Level 8 (38,171 points)
    Mac OS X
    Sep 25, 2016 4:54 PM in response to rgomez

    Do you have any open pages in Safari? Try closing all open pages. Some pages autoupdate, and each page load can require multiple DNS requests.

  • by rgomez,

    rgomez rgomez Sep 25, 2016 5:18 PM in response to Lawrence Finch
    Level 1 (9 points)
    iPhone
    Sep 25, 2016 5:18 PM in response to Lawrence Finch

    Hello,

     

    No, I don't usually browse the web on the iPhone. And 466MB of DNS requests (in 90 minutes in my case!) are something like 5 billion requests... maybe the total requests made by normal usage in 10 years or so. This is a more subtle problem. Quite probably some app (or the iOS itself) has a bug that causes a loop of DNS requests. That' the only explanation.

     

    Just for comparision: how much DNS services you have on your own usage? I venture that it will be at most .05% of the total usage of cellular data you have (the iPhones I have checked usually have around .015% or .020% of the usage). That's what would be normal. Anything above 1% I would start wondering what's going on.

  • by Lawrence Finch,

    Lawrence Finch Lawrence Finch Sep 25, 2016 5:24 PM in response to rgomez
    Level 8 (38,171 points)
    Mac OS X
    Sep 25, 2016 5:24 PM in response to rgomez

    My DNS usage is 6.2 MB for half my billing period. There's clearly something wrong with your phone; perhaps a corrupted DNS server address. So the first thing I'd suggest is to Settings/General/Reset - Reset Network Settings. This should set all network settings back to the default, including your WiFi passwords and settings. I'd also check for a carrier settings update by going to Settings/General/About and tapping on the carrier's name. I know that Verizon and T-Mobile have issued carrier settings updates, and that T-Mobile's was necessary for the phone to work at all.

  • by rgomez,

    rgomez rgomez Sep 25, 2016 5:26 PM in response to Gualberto_N
    Level 1 (9 points)
    iPhone
    Sep 25, 2016 5:26 PM in response to Gualberto_N

    Hello Gualberto,

     

    Do please contact Apple Support!!! (either by phone or by chat, although I think it's much better by phone) and let them know.

     

    I spoke today with a helpful person that escalated the issue and it is now, in theory, in the Engineering Department. They will probably need logs or something similar from my iPhone, but having another case will make finding the cause of this much much easier. I'm a developer myself so I know that in cases like this, it's better to have as many cases as possible.

     

    You might need to restore your devices from a backup, and so on (they will ask for all this before even passing your case with someone higher up) but in any case, there is no way to generate 2Gb of DNS requests with a device like this. There is clearly something very wrong that is causing that.

     

    Let me know what happens when you contact Apple Support. It could maybe be a good idea to mention that there is another report that was already escalated of this same problem.

     

    As a suggestion: take screenshots of the statistics every now and then (I'm usually doing so every time I will go out of a Wifi network, and when I return), that will help you present your case to Apple (I sent the ones I had).

  • by rgomez,

    rgomez rgomez Sep 25, 2016 5:34 PM in response to Lawrence Finch
    Level 1 (9 points)
    iPhone
    Sep 25, 2016 5:34 PM in response to Lawrence Finch

    I did that the day I found this issue (on sept 16th). It did not help. Later I restored the iPhone completely, it didn't help either.

     

    There were some carrier updates, IIRC, around the same time iOS 10 was released. This started happening 1 week later. It could certainly be the problem, and I have checked every day if there is another update, but so far nothing.

     

    I have thought about using some of the apps that allow one to modify the DNS server used for the cellular data, but right now I will wait for Apple to contact me with the response. They said it will take them 24-48 hours to hear back from the Engineering Department.

     

    Today I was monitoring the DNS traffic using my own firewall, but it did not show any abnormal behavior.

     

    I forgot to add: I have access to 2 other iPhones running iOS 10 (and with the carrier update installed) and with the same carrier as I and those iPhones have not shown this problem so far. We don't have the same apps, but the ones I use the most are in fact used also in those 2 devices.

  • by Gualberto_N,

    Gualberto_N Gualberto_N Sep 25, 2016 8:33 PM in response to rgomez
    Level 1 (4 points)
    iPhone
    Sep 25, 2016 8:33 PM in response to rgomez

    OK, thank you.

     

    I will do that and post here the results.

  • by rgomez,

    rgomez rgomez Oct 2, 2016 6:23 PM in response to rgomez
    Level 1 (9 points)
    iPhone
    Oct 2, 2016 6:23 PM in response to rgomez

    Well, this keeps happening. I contacted AppleCare one week ago, and the woman who attended me was very responsive and apparently she did understand the problem. She was going to contact someone higher up, and then, in 24-48 hours, contact me.

     

    1 week later, and 4 emails from my part to she, I haven't got any reply at all. What I did get was some 100MB or so of DNS traffic. I also think that the Location and Time services are using more than needed... but without help from Apple it's impossible for me to track down what application is causing it, and I'm almost sure it's no App that can be disabled from the cellular data configuration (as I have had traffic even with all apps disabled there).

     

    I am now on another country (Canada), with another carrier (although using my mexican contract with AT&T, that includes roaming in USA and Canada) and it still happens (got 12MB today). So it's not that the DNS server assigned by my carrier is returning corrupted records, as now I'm using another DNS altogether.


    I will try going to an Apple Store and see if the Genius bar has something to offer me, but as I don't think this is a hardware problem, I can only hope that they can check the logs of the iPhone directly and see what DNS requests are being made (that was my original intention with the call to AppleCare) and that could probably give an idea of where the problem is... but I don't know if they can in fact access those logs, or even if there are logs for the DNS requests being made at all.