I managed to make an openvpn-connection from behind proxy as well as 3G. TCP is activated on server as well as on client and works pretty well.
However I do have some additional questions I would like to have an answer to in this ticket:
*Is Webadmin page (see below) also possible for Synology NAS?
I can ssh to my nas, but how to continue to install the webadmin?
*Which traffic to route for client: just want Internet and my home addresses to be routed, work network should stay at work of course? iow = best practises
*how much traffic maintaining such a tunnel takes?
*in logfile: WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this
How to disable this correctly?