DDNS does not close anything, it simply automatically makes the mapping of your external IP to a public DNS name and publishes it in the global DNS.
The provider is quite possible, not all providers allow all ports towards the user
Router - also possible, here is the question of which promise and what you did. If you proceed from logic, the router starts the Trasmichn locally on its hardware, you can see it from the internal network as 192.168.x.1: the port, but the Web can be closed to the external address. Making a forwarding on 192.168.x.1 does not make sense, and the router will not give, you need to look if the security settings are prohibiting connections from outside to the external IP router. You can also see the settings of the transmission itself can there be something to twist something, but as far as I remember them there is not a lot of.
Posted on 01/18/2016, 12:35: Pelbmehb @ 01/18/2016, 12:34
IP 192.168.31.2
Whose address is it?