Nextcloud unable to connect via WLAN at home

Hi everyone,

i’m new here and new in the field of dns routing. So please be soft on me :slight_smile:

My Problem is the following. Im using this service to connect my Nextcloud (NC) with my mobile. Via the carrier this works fine so far. The problem starts at home when my mobile is connected with my home Wlan.

Every now and than my NC client on my Android phone can’t connect to my NC (which is running on an ThinkCentre Client PC under Xubuntu) and i have absolutly no idea why.
When i compare the IPv4 and IPv6 adresses under deSEC Domain Management Tab, it states the same adresses as my FritzBox. So they seem to be in sync.

When i press the “new connect” button (Fritzbox: Internet → Online Monitor), the FritzBox gets new IP Addresses and hands them over to deSEC

Than the game starts from the beginning, meaning i have connection on my mobile via WLAN for 1 or 2 or 3 or 4 days until it’s broken again.

Does anyone have a clue what’s causing this?

Thank you very much in advanve,
Your Ferdi

Hi Ferdi

First of all, this has nothing to do with deSEC. Now with that out of the way, here is what I think is causing the problem:

Read the Network and the Split DNS Part

Nextcloud does not always use IPv6 instead of IPv4.
I had the same issue. I solved it by creating an unbound rule on my firewall. This is unfortunately not possible with fritzbox.

But for testing, you could delete the AAAA record. If my theory is right, you should then not be able to connect to your Nextcloud at all (maybe over IP, but not over the domain name).