Hi,
I just tried to configure my first Nextcloud test server, but I’m already encountering problems with the port forwarding in FritzBox:
I have configured a port forwarding of port 80 (to 80 internally) and 443 (to 443 internally). If I access my xyz.duckdns.org address I can only see the FritzBox interface. If I access the https://12.456.246.78 (external IP) I can directly access my server in the network (port forwarding works). If I configure 44344 (to 443 internall) I can also access my server via xyz.duckdns.org:44344
So, I don’t understand the problem. Only external IP works, with duckdns it doesn’t work, with separate port it works again.
By the way I found a lot of problems like this already described, but the typical solution is to deactivate the FritzBox remote connection. For my configuration it is independent whether the FritzBox services are activated or deactivated → always same issue.
Can anyone explain this behavior or knows how to configure correctly? I want to avoid the separate port
Thank you, I was in contact with FritzBox support: I don’t have an explanation, but this only occurs in case I try access directly from home network. It works from outside…
As i wrote before… It’s a FritzBox-Config-Problem. FritzBox use by default a DNS rebind protection. For detailed infos view FritzBox support.
In general, DNS rebinding protection is a security mechanism to prevent DNS rebinding-based attacks. Home routers include a protection mechanism against this attack by never returning a local IP address (v4 & v6).
To use this you have to add all FQDNames that are on your local network to the networksettings in the Fritz!.
Go to Home Network → Network and then the tab networksettings.
Scroll to bottom and see 'DNS-rebind block.
Add there your local FQDNames under Exeptions.
Then it should work perfect and the is noo need to use IP addresses. I’ve about 18 names there for all (sub)domains that are on my Synology, virtial machines and docker.
