The simplest most straightforward way is to have a NIC on your Ignition Gateway (Server) on the same subNet as your BACnet devices. If you need additional networking requirements to e.g. run Vision Clients or Perspective sessions across your Corporate LAN, then again add a NIC dedicated to that.
There are other ways such as routers, but as you mention corporate then IT will want to get involved with that.
So it sounds like you're pretty much on the right track.
Again, you can download the Ignition full version for free in 2-hour demo. There may be some differences in how Ignition addresses end devices with its driver compared to your BMS syntax.