Remotely access LAN with UDP autodiscover for media devices

  • Any help is greatly appreciated!

    The client has a CCTV server and hardware CCTV decoders with HDMI output.
    They are auto-discovered and configured by the CCTV server software when on the same LAN.

    My problem is that the client wants to have a few of the CCTV viewers offsite, so this will require VPN

    I installed pfSense in VMWare, with 2 virtual NICs on 2 virtual switches - WAN side connects to ISP's router, and LAN side connects to CCTV network switch.
    Configured WAN interface with  dedicated static external IP, and LAN interface without DHCP is connected to the CCTV network, with the gateway pointing to the CCTV network's existing router.

    At this point I am lost ;-(
    IPsec / L2TP configurations imply virtual subnets and IPs, but what I would like to do is for the VPN client (some tp-link box probably) is to connect to pfSense, and get a local CCTV network's IP using DHCP from existing CCTV network's router

    Many thanks for any help!