I am using Ubuntu 12.04 VPS to host a PPTP server for my own personal use. I have set it up using a script I have written myself which is drawn from various different tutorials I have come across online (http://www.markmearns.com/sandbox/pptp.sh).
The service installs fine and I can connect to it using any Windows machine using built-in VPN clients, via my iPhone and Android tablet. The connection works fine and all traffic is routed over the VPN. It works quickly and never drops out.
However, I have invested in a Mikrotik routerboard as I want a wifi network that just routes over the VPN. The router connects to the PPTP server, but after about 1m20s it disconnects and reconnects. The VPN server also does not exchange any data with the router.
The router and its settings are working fine as I can connect to commercial PPTP VPN services (like hidemyass.com) and the connection works fine and never drops out. This leads to me to believe that the router is not at fault, but my PPTP server is the problem.
Would be grateful if anyone could shed any light on this for me. The configuration is obviously that as seen in the script I have written.