I am a controls engineer using VMWare to run VM's that hold several legacy versions of Rockwell Software RSLogix and Studio 5000 software for PLC programming. This means that my work requires me to connect to PLC's and other devices over Ethernet connections often, with many unique situations to be found.

In order to use Rockwell's proprietary OPC communications tool, RSLinx, in the VM, the common knowledge of my company is to use a Bridged connection directly to our main physical Ethernet adapter on the Host. It allows us to find devices on a given network more easily and create links for constant communications as needed. NAT does work for external connections, but it confuses RSLinx when run from the VM, which defeats the point of using the VM for all of the legacy programs. In the past (and quite ideally), our customers have given me 2 IP's for my Host and my VM on the same network with a 255.255.255.0 subnet mask. My problem comes with a unique customer situation that leaves me stumped:

My customer has given me two IP addresses (subnet masks in parentheses) that they have spare on their wider controls network:

Host: 10.136.4.65 (255.255.0.0)

VM: 10.136.7.65 (255.255.0.0)

These two work great to access devices on both the 10.136.4.xxx and 10.136.7.xxx network given the proper subnet. My problems come in where there are some devices to which I would like to connect for reference purposes that are on the 10.136.4.xxx network, but they were set up with a 255.255.255.0 subnet mask. I can ping them and see them in RSLinx on my host (obviously, being on the same network regardless of subnet mask), but I cannot do so on my VM. I cannot change their subnet mask settings as I am a contractor, so here is my main question:

In this situation, is there an alternate way to preserve the functionality that a Bridged connection affords me when using RSLinx while also allowing me to connect strictly to the 10.136.4.xxx network alone?

I will ask Rockwell's knowledgebase as well, but I have started here first as it is possibly the simpler answer.

Go easy on me; my networking skills are probably much more rudimentary than what IT power users have.