Routing in VPN networks

Suporte Speedtech

The scenario is as follows: we need to route access to a device on the network that is under a router connected by PFSense VPN (OpenVPN).

The PFSense server is far away from the site and must serve as DHCP. We create a specific VPN subnet to connect our in-site routers.
The local router is a Novus Airgate-4G connected by SIM Card WLAN (there is no wired internet close to the plant). We want it to be a bridge or access point only, no DHCP.
The equipment under the local router is an automated IoT, with a simple panel, which will send control data and should allow remote maintenance.
For remote maintenance, we must create routes between the technicians' computers and the IoT equipment (like NAT).

In our tests, it was not possible to set the PFSense VPN Server as the subnet's DHCP and therefore no routing was possible (we had to enable DHCP on the Novus router and create a DMZ. This worked with 01 IoT device, but we will put more soon and it will become a problem)

Is what we are planning possible? Can PFSense be the remote DHCP server of a VPN network? If so, how do we route the PFSense Server, since VPN services don't have advanced routing tools (not that I've seen)?

Thank you in advance for your time, attention and help.

Suporte Speedtech

@suporte-speedtech Up