DNS causing problems

Discussion in 'Technical Support (AdGuard for Android)' started by tox1c90, Jun 1, 2019.

  1. tox1c90

    tox1c90 Beta Tester

    Joined:
    Apr 27, 2014
    Messages:
    73
    Hi!

    I noticed that for some apps, setting a custom DNS in AdGuard seems to be problematic.
    I disabled local DNS filtering (black hole) and I was just using Cloudflare DNS, so there is no DNS filtering involved.
    I noticed problems with the following two apps:

    - DriveNow Car Sharing (it takes ages for it to show you the available cars when DNS is enabled in AdGuard)
    - Outlook (I got push notification about new mail, but Outlook was unable to show it in my inbox. Even after manual refresh it was not showing the new email. After disabling DNS in AdGuard, the mail showed up after next manual refresh)

    So this is kind of strange, because Cloudflare does no filtering and I disabled the local DNS black hole filtering.
    It looks like just the mechanism alone of AdGuard re-routing DNS requests seems to cause problems. Do you have any idea why?

    (Or is it due to some really stupid stuff like Microsoft or DriveNow servers failing some DNSSEC verification of Cloudflare?)
     
  2. Davey126

    Davey126 New Member

    Joined:
    Nov 17, 2014
    Messages:
    27
    Yep, same issue here. Enabling DNS redirect (no filtering) effectively blocks wifi when configured as a VPN. Works fine in proxy mode. Log shows unusually long DNS resolution times (10+ sec) but no explicit errors. Likely due to some device/ROM weirdness. It did work in AdGuard builds prior to v3.1.0 (1.3.347cl). I have cleared local caches and reconfigured AdGuard to no avail. I have not officially reported the problem as I have experienced the approach used by tech support: wear you down by requesting everything (I value my left n#t) then deny the problem exists. Simply not worth the effort/aggravation.