Hi Many thanks for your reply! I tested that and I found that I actually couldn’t access it (no IP address) from my Android browser which is strange because anywhere else (home PC, Laptop, PC at work, Thunderbird…) I’ve always had access. So I looked up the NAS’s IP address on my modem and when I use the IP itself in DAVx5 it worked!! So I assume this has something to do with static/dynamic IP addresses, what do you think? I assumed my NAS has a static address because I can always login with the same address (monolith:5000) but I guess I was just lucky that when I updated it, it received the same address after restart. I bought it half a year ago… So long story short, I’ll have to make sure that this address is static and it will keep on working/synchronizing or do you think the problem lies somewhere else? Your help is highly appreciated, thanks again!

@rfc2822 said in Cannot sync with local server without internet connection: Android won’t start synchronization (= call the DAVx⁵ sync adapter) without Internet access. OH COME ON!!! why is it so bloody hard to do ANYTHING with a properly air gaped device? There has to be a way around this! I should NOT need to connect to the internet at large in order to sync my tablet to a nextcloud hosted on a LAN. Is there a way I can trick my tablet into thinking its connecting to the internet? Is there a way I can use another caldav app that does not rely on andoirds sync service? there has to be a way around this without me rooting my tablet.``` Insert Code Here

@rfc2822 said in Option to change the IP address for the server: What don’t you just create a WiFi with your notebook and use this WiFi from your phone? Or, the other way, create a WiFi on your phone (tethering) and then connect with the notebook to this WiFi? That is what I actually do already! I connect the phone with the hotspot of the notebook because that is much faster than the Wifi network. But the hotspot IP did not work, only the IP of the notebook in the Wifi network. Your answer prompted me to check this again. Probably it was a missing firewall rule. Now it works! I use the hotspot of the notebook because that IP and therefore the server address remains the same (192.168.137.1), the IP of the phone changes with every new connection to the hotspot. So thank you very much for addressing this! (How) can I add the “solved” tag to this thread?

@tartarian said in DavX thinks there is no internet even though there is: That is fine but it would be nice if the app does not rely on the system’s false flags if it is conenected or not. Maybe some kind of override would be nice for sure. DAVx⁵ is a sync adapter and relies on the synchronization framework of Android. If Android thinks there is not internet connection, it won’t call DAVx⁵ for synchronization. Please make sure that Android APIs work as documented on your phone; otherwise apps which use those APIs can’t work well. DAVx⁵ relies on working Android APIs, like many other apps. For instance, you won’t be able to receive emails or sync your Firefox data “without Internet connection” as well. I suggest to change the captive portal URL to something on your own server and de-block the connectivity check in your firewall. BTW, it’s called DAVx⁵ or DAVx5. Please don’t call it DavX.

Hello, 2019-11-30 09:49:10 10217 [HttpClient] <-- HTTP FAILED: java.net.ConnectException: Failed to connect to /192.168.0.100:8443 2019-11-30 09:49:10 10217 [ui.setup.DavResourceFinder] PROPFIND/OPTIONS on user-given URL failed There is no connection to 192.168.0.100:8443 from your Android device, so it’s probably a connectivity problem (firewall, …). Does it work when you access the URL from your Android browser?

In DAVx⁵ 2.6, there will be a warning when there’s no validated Internet connection. So when you see this, you will know there’s something wrong with the connection:

Thanks for the explanation. I guess it was a problem with Baïkal after all. I have “fixed” it by switching to DAViCal. Very intimidating documentation & UI, but almost nothing needed to be configured and it Just Worked. So, DAViCal is the server DAVx5 syncs everything on Android on the desktop I use vdirsyncer & khal for the calendar only (vdirsyncer still refuses to sync my contacts), and SoGo connector for contacts on thunderbird. It’s been a long day.

@pescepalla Thank’s a lot! Your solution workes on my Xiaomi 5s plus with nextcloud on an own server in my LAN and using DAVx⁵ for synchronisation after I’ve searched two days where the problem comes from. By accident I installed nextcloud 15 and deleted and reconfigured DAVx⁵’s account. So I was not clear if it’s a nextcloud or a DAVx⁵ problem. Finally I found out in the nextcloud logs an entry webdav Sabre\DAV\Exception\NotAuthenticated: No public access to this resource., No 'Authorization: Basic' header found. Either the client didn't send one, or the server is misconfigured, No 'Authorization: Bearer' header found. Either the client didn't send one, or the server is mis-configured, No 'Authorization: Basic' header found. Either the client didn't send one, or the server is misconfigured Still misleading, I checked everything related with passwords and accounts. Android doesn’t sync if it can’t connect to a working captive_portal_https_url, even if you choosed in the internet access settings for your network not to ask the question anymore and the internet works as far, as possible in China. And that with LineageOs. As many people not only using their own local nextcloud installation inside a LAN that is kind of a strange setting with Android in China at least. Thanks again, @pescepalla !

Confirm the regression too. got I9300 with replicant 6.0 0003 Long time ago, add account to davdroid installed from f-droid. Following upgrade from f-droid repository and work well with latest version of Davx5. But have to reinstall os, reinstall Davx5, and cant register new account with the same stack of error when trying this url: https://domain.tld/baikal/html/dav.php And when trying https://domain.tld/baikal/html/dav.php/calendars/user/work/, Davx5 print crash popup. Install an old davdroid apk and work well. Work well with Thunderbird too for calendar and Inverse SOGo Connector for address book. Not a server side problem. Thanks a lot for this software ! Happy to use it daily.

@devvv4ever Sorry for the delay in responding. I used the IP instead of the name, but I get the same result. Here is the log davx5-info.txt Any thought will be greatly appreciated.

@mazeiva I don’t know. We’d have to know the actual reason why it’s not working to say why it’s working on other devices. Maybe you can find something in your server (for instance, do the DAVx⁵/browser requests make it through to the server) and/or firewall logs?

Is it possible that you have multifactor turned on for Nextcloud? If so, you can create a one-time password in your NC settings.

@moonlies Did you use an app password for the first account? In this case, the app password would stay valid even when the main password changes.

@rfc2822, may application was moved back to the old server. now all cipherspecs are available again, nothing was changed on the old server ! Only my Nextcloud was first migrated to a newer server, there Nextcloud was updated from 13.0.7 to 14.0.4, the problems occurred. now the Nextcloud has been moved back to the old server. But now it is still Nextcloud 14.0.4 ! Could it be that it’s not the cipherspecs but the old DavDroid has a problem with Nextcloud 14.0.4?

Hello I’m running owncloud 10.0.0.4 on a slow system and requesting a contact sync >450 entries (with pictures). As far as i’m able to judge the client is requesting the whole addressbook and after timeout exception it want to retry a request of 10 entries. At this time the server is still running at 100% cpu duty collecting the previous request. That leads to a bunch of apache instances on server-side which freezes the system for a couple of minutes and the client isn’t getting it’s requests within it’s (too short and unconfigurable) timeout. For reference: setting the timeout to 180sec would very likely fix this problem

I had the same problem where I was able to enter my account in davdroid and Davdroid itself successfully found all my calendars, however none of them would sync with the phone’s calendar programs (both the native calendar and e-tar). Seems like a bug / change in android 7 broke calendar syncing. I was unable to get davdroid to work for months, however now that there’s a new DAVx5 client I decided to try it. They fixed it! The link is broken in the fdroid repo’s BTW, however I managed to install davx5 manually and everything’s working. So if anyone else has the same issue, give the new davx5 a shot!

@rfc2822 No, I can’t browse to the server from any device connected via Internet. On my local LAN the web pages serve up fine , and my Thunderbird calendar on a machine on the LAN will sync to the calendar on the Pi. However, I can ping the server successfully from the internet - both via direct IP address and the sub-domain name. I do have a local DNS server running on another RPi on my LAN - Pi-Hole - to block ads. The Pi-hole logs don’t indicate that traffic to the sub-domain are blocked. But the DNS blocking would be happening from DNS resolution requests from devices that are connected on the LAN, not traffic coming into the LAN.

Hi, Thanks, it’s also the issue I was having. Instead of giving internet access to uid 1000, I just did “settings put global captive_portal_mode 0” (recent android) Agreed it would be useful to add this in the FAQ

I had the same problem with DAVdroid and Posteo and found the cause, so I wanted to share this: I am using LineageOS 14.1 on a GT-i9300 (Samsung Galaxy S3) in Austria, my mobile telecommunications operator is A1. As far as I remember I never edited the APN settings after setting up my phone, so I suspect that the default APN for this operator is wrong (sure it’s possible I edited the settings and can’t remember it…). The active APN was named “live!” and used a Proxy – and I ran into the problem described here. After changing the APN to “A1” (settings with the name of my mobile telecommunications operator and without a Proxy) I can’t reproduce this issue. You can find all APN settings included in LineageOS on GitHub. BTW, thanks for DAVdroid!!