OpenVPN works but qnap cannot be contacted from VPN clients
I setup succesfully OpenVPN, my clients are able to connect to network and are able to contact/connect all clients of PfSense which are using PfSense as its gateway.
But I have one device (in fact Qnap storage) with 2 NICs, one connect to switch of PfSense and another do different network. Routing is possible only via one network so I am using that 2nd network as gateway.
IP address of qnap in PfSense network is 192.168.0.110, I can ping that address from PfSense via LAN, but not via OpenVPN.
Also no OpenVPN client is able to ping/connect to qnap.
Can you advice?
It's quite possible that the Qnap won't accept traffic from any network outside the LAN it's attached to. The traffic from your OpenVPN connection appears to come from your OpenVPN network address.
Have a look at this thread. Substitute your subnets/addresses into jimp's solution and see if it works.
Edit: I don't know about the Qnap but you may also be able to configure the networks allowed to talk to it, as you can in NAS4Free.