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Does NextDNS use Cloudflare's Network Error Logging (NEL) system?

Even when not using any Cloudflare products or services or accessing any website other than my.nextdns.io and with all extensions disabled, my browser (Google Chrome and I know it's the browser because I used a separate name for it in the DoH URL.) tries to connect to " a.nel.cloudflare.com", which I assume is the domain used by Cloudflare's Network Error Logging (NEL) system. Hence the question: does NextDNS in any way make use of "a.nel.cloudflare.com"? Or could it be made by something within my own system?

(I'm not posting this as a bug report as it doesn't seem like a bug to me. I hope I'm not violating any posting categorization rules) 

Thank you.

9 replies

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    • NextDNs
    • 3 yrs ago
    • Reported - view

    We do not. Do you see this domain in your NextDNS logs?

      • Nest_Eagle
      • 3 yrs ago
      • Reported - view

      NextDNS Thank you for the reply. Yes, I see "a.nel.cloudflare.com" in my NextDNS logs. But as you can see in the image that it is being blocked by a filter list (1Hosts Pro). It could be something within Chrome, or my own system, I will try and test more scenarios.

      • Nest_Eagle
      • 3 yrs ago
      • Reported - view

      NextDNS Hello again. After doing some tests with different scenarios (such as different browsers, devices and NextDNS configurations etc.) I have determined the steps to reproduce the issue. (I am not technologically sound but I have tried my best)

      Steps:

      1. Set up a NextDNS config on a Google Chrome browser or set up one using the NextDNS desktop application

      2. Use a separate browser that is not Google Chrome (e.g. Firefox) or preferably another device to monitor the logs of the NextDNS config

      3. Clear the cache of the Google Chrome browser (a fresh profile is preferred)

      4. Open Google Chrome and visit https://my.nextdns.io (logging in is not strictly necessary)

      5. And inspect logs and you may find "a.nel.cloudflare.com" requested from Google Chrome and it may happen every time Google Chrome is opened and https://my.nextdns.io is accessed.

      My findings: 

      1. Only Google Chrome Stable, Google Chrome Dev and Google Chrome for Android has this issue (if we may call it one). Firefox Nightly, Firefox for Android, an Ungoogled Chromium installation do not have this issue.

      2. Only browsing https://my.nextdns.io causes this issue.

      3. Requests to "a.nel.cloudflare.com" are made at irregular intervals (2 to 5 minutes apart)

      Thank you.

      • MaxMT
      • 3 yrs ago
      • Reported - view

      Nest Eagle I have come across the very same issue on a chrome book pixel book go running stable 91+ current. I believe I know where this stems from but need to do some testing and sort out some odd things I did not expect to see. 
      initially, I hit the drop down in the Secure DNS section in chrome settings and was super surprised to not see NextDNS as one of the default DNS providers. 
      Questions @NextDNS is there a reason in 91 Chrome OS stable you aren’t a default?

      I tried to just add the DoH url string to the  custom provider after I had no other choice and kicked me an error that this wasn’t a valid provider . Wouldn’t take. Logged in to My next account and it said wasn’t configured was resolving to Cloudflare. 

      so I then went to google play and installed the native App and added my acct number for the app. Connected up got a green light on the setup page. But the logs were kicking the a.nel.cloudflare network error. So something is real wacky .  But looks like the browser is still trying to resolve with its default  cloudflare… 

      • MaxMT
      • 3 yrs ago
      • Reported - view

      NextDNS see above reply

      @nest eagle 

      • SLCW
      • 3 yrs ago
      • Reported - view

      Nest Eagle I know you said the problem is triggered by browsing my.nextdns.io, but have you dug deeper into the logs to see if it's triggered by any other host? It's a pretty important question because if it truly is only NextDNS that triggers the problem, then it's reasonable to suspect that NextDNS is the cause. But, if the problem is actually triggered by some function across multiple hosts,
      thenit no
      longer makes sense to look at the NextDNS site as the cause.

      Based on your description, I suspect this issue originates with Chrome,
      but warrants
      further investigation to identify and isolate. Have you tried using a chromium-based browser?

      • Alhavolka
      • 1 yr ago
      • Reported - view

      Nest Eagle What the fuck?

    • Nest_Eagle
    • 3 yrs ago
    • Reported - view

    I'd like to again assert that my testing may be flawed or the steps I provided may not work and my findings may in fact be false. But I would appreciate any third person perspective on this as I can't seem to find the source of this "phantom" which it may as well be. Thank you and apologies in advance if this causes any wastage of your time.

    • Shadow_Colossus
    • 3 yrs ago
    • Reported - view

    This problem is curious, it may have some connection with the leak problem that some users are having with the service: https://help.nextdns.io/t/q6hkgrc/dns-leak-test-showing-CloudFlare-Addresses-Instead-of-Local-NextDNS ?

    Have you ever tried to do a DNS leak test to see if CloudFlare servers show up in the leak? If you haven't done it yet, I ask that you please take the test, there may be some connection with what I went through.

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