Generating your Certificate Authority (CA) is necessary to validate the OpenVPN server’s identity and authenticate user certificates. Within pfSense, select System, and then Cert. Manager.

Click the network port from which the Netgear VPN users connect. Typically, this is "fpx0" or "fpx1" if using a Wi-Fi connection. Click the "Save" button. Click the "Interface" menu item again.

If I use our client access VPN, that gives me an IP in 192.168.255.x/24, but I can't use that VPN with all of the devices that I want to, plus it requires manual establishment (another step).

pfSense software is a free, open source customized distribution of FreeBSD that delivers high-performance secure networking firewall, router and VPN solutions.