I want to ask you guys how to solve this, and here is my setup:
SERVER SIDE (OPENVPN)
1. Gateway address: 192.168.0.1/24 - Linksys ADSL router
2. OpenVPN server (LAN address 192.168.0.80/24 and Virtual address: 10.8.0.0/24, DHCP for VPN clients from range 10.8.0.6-10.8.0.x)
3. WAN IP: 32.xxx.xxx.xxx (not important)
CLIENT SIDE (OPENVPN Client)
1. Gateway address : 192.168.1.1 and OpenVPN client at the same time
2. Virtual address (gets from DHCP Server OpenVPN) : 10.8.0.6 - 10.8.0.X
3. Other Device is connected on the same LAN with IP: 192.168.1.100/24 (Gateway: 192.168.1.1) with service on port XXX started
4. WAN IP : xxx.xxx.xxx.xxx (not important)
So, here is what I want (which is very simple on paper

I want to enter SERVER_SIDE_IP : XXX so that I can access directly to that service on OpenVPN client connected.
And here is (where I'm now) :
1. I can ping from OpenVPN client all address on SERVER SIDE in range 10.8.0.0/24 and 192.168.0.0/24 (that's expected) (192.168.0.1, 192.168.0.x, 10.8.0.1 .etc)
2. I also redirect-gateway and my OpenVPN clients gets WAN IP from my SERVER (that's expected)
But here is trouble:
1. How to define Fixed IP address for OpenVPN client in range 192.168.0.x so that I can port forward on my Server's Gateway so that I can access to my XXX port on VPN Client side.
In other words my clients gets 10.8.0.x range but I want for them one fixed IP in range 192.168.0.x so that I can port forward on Server's side and access to that service through it directly.
Best Regards,
Zinky