I have a Asus RT-AC66U AC1750 Router which provides a VPN Server. For the Connection it uses PPTP. This Router is connectet to my Thomson TWG87OUG Modem which provides me with a internet connection from UPC. The Modem is set to forward the 1723, which should be the Port form the PPTP. So thats the basic setup. Now if I try to connect to the VPN Server with my Android Phone it tells me that the server does not react on the request.
I googled around but I can't figure out why this doesn't work. I already had some Problems with the Modem but with forwarding I could get https and ssh to work. But now I am stuck with the VPN.