Cannot sync to local server without internet connectivity



  • Hi,
    yes indeed DAVx5 does tell me there is no internet connectivity. But that is the point : there IS network connectivity !
    Just no connectivity towards whatever server you use to check internet connectivity. 😉
    The phone is on the local network ( 192.168.x.y ) and the CalDAV server sits on the same network ( 192.168.x.z , one WAP and 2 ethernet switches between them ) with full connectivity between both devices (easily checked with an HTTP connection to the server from a browser on the phone).
    In this situation I would expect the CalDAV sync to happen flawlessly…but nothing happens.
    Is this something you can help with ?
    Thanks


  • developer

    @Thierry-Palijn said in Cannot sync to local server without internet connectivity:

    yes indeed DAVx5 does tell me there is no internet connectivity. But that is the point : there IS network connectivity !
    Just no connectivity towards whatever server you use to check internet connectivity.

    We do not check. The Android framework checks that.

    When Android tells DAVx5 that there is no Internet connectivity, you will see that messages and Android won’t schedule any syncs.



  • Ah. So in essence are you telling me you cannot solve the issue because you’re dependent on Android goodwill ? 😢


  • admin

    Yes… 😕



  • Thanks for your help anyway !

    For the record and anyone interested, I am looking into hacking the network to make Android believe there is internet connectivity.
    More extensive information there : https://foxdogstudios.com/blog/making-phones-believe-the-wifi-has-internet


  • developer

    Well in 99% of the use cases (including my own one), the check makes perfectly sense, because the remote server is in the Internet and syncing would fail without Internet.

    So I wouldn’t call that goodwill, but rather say the system isn’t designed for non-Internet use cases. DAVx5 uses the Android system, so it inherits this design decision.

    It would be possible to adapt DAVx5, but it’s (much?) work and not top priority.



  • @rfc2822 sure, if you consider that “the internet” consists only in a handful of Google-owned servers, then yes Android (no surprise here given it’s now designed by… Google) is not designed to work without “the internet”.😑
    I personally tend to disagree with these expectations, having been roaming the internet pathways since long before Google even existed. But then I am a dinosaur and expect things from my network that might seem “non-standard” nowadays.😲


  • developer

    @Thierry-Palijn said in Cannot sync to local server without internet connectivity:

    @rfc2822 sure, if you consider that “the internet” consists only in a handful of Google-owned servers, then yes Android (no surprise here given it’s now designed by… Google) is not designed to work without “the internet”.😑

    Technically, you can change the captive portal URL. See https://forums.bitfire.at/post/10877, for example. So you don’t depend on Google, but only an “Internet” check. (And of course you need high skills and maybe a rooted device to change these things.)

    I personally tend to disagree with these expectations, having been roaming the internet pathways since long before Google even existed. But then I am a dinosaur and expect things from my network that might seem “non-standard” nowadays.😲

    I agree that your usecase is perfectly valid. On the other side, I understand the Android sync framework and that it depends on determining general “Internet” accessibility, and then starts all kind of syncs when Internet is available. But I wont defend Google’s design decisions because they’re not my own ones. It’s just like it is.



  • @rfc2822 We seem to agree just fine 🙂
    Thanks for the ‘settings’ info !
    I use DNS spoofing on the server-side instead (does not require root, but obviously some skills with a DNS server) ; probably more of a hack than yours 😉


  • developer

    So it’s solved for you? Fine, I’ll set the topic to resolved.

    Maybe supporting local syncs without Internet will be possible with DAVx5 some day (I’d love to see that). But first there are many things to do 😉



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