DNS: pass DHCP lease via pfsense_ovpn_client => OVPN_Server => OVPN_Client

[Vetal]

I created following setup to expose services from my internal network bullet proof way, e.g. from behind the firewall.

It was a common way:

Client => pfsense NAT/Port-forwarding => Server,

where pfsense WAN is advertized via DynDNS

I did following set up, using this instructions from http://openvpn.net/index.php/open-source/documentation/howto.html#scope:

[Client OpenVPN ] => [VPS (Digital Ocean) with OpenVPN Server] <= [pfSense, OpenVPN Client] <=> [internal servers (192.168.5.0/24)]

OpenVPN lives on 10.8.0.0/24. All config is concentrated on OpenVPN server, pushing pfsense LAN 192.168.5.0/24 with route/iroute to the external client (on the left). So I can access any machine by the external client on pfsense subnet via pfSense LAN IP, given I have it allowed on OpenVPN firewall page.

It works perfectly, though I want to provide DHCP leases info to the client. So, client can access server 192.168.5.5 on pfSense LAN. With "some-server.mydomain", not by IP. The same way I can do it within pfSense LAN, where DNS request come to DNS Forwarder of pfSense, where I have " Register DHCP leases in DNS forwarder" option set.

How can I pass this DNS to external client, while leaving the rest of DNS for him untouched. Or, at least, pushing google DNS?

External client does not have his gateway redirected, so everything outside of VPN subnet and pushed subnets goes as usual.