Can NICs/vSwitches be 'shared' on a Hyper-V 2016 host?

I've been reading documentation until my vision is blurred.

I'm sure this has a simple solution, but all the docs I'm finding go into excruciating detail on how to set something up—nothing on whether a particular configuration is a good fit for my situation.

I have a Hyper-V 2016 host with two physical NICs. All the VMs (PDC included) are bound to a vSwitch that's bound to one of the NICs; that cable goes to a physical switch to which all the workstations are connected. Straightforward stuff. It's been working for years.

Now I need to plug a NAS device into the second physical NIC so that it can see the PDC on the first. (I can't plug the NAS into the physical switch because that switch has to stay at 10/100 for our older CAT5 cabling. The NAS needs Gb speeds. We tried a Gb switch there and we were getting intermittent dropped connections on workstations.)

Is VLAN the solution for this? Teaming? Bridging? I'm lost, I'm afraid. And my eyes are swimming for the tech docs I'm trying to decode.

The NICs are 192.168.2.11 and 192.168.2.21, respectively. The VMs are on 192.168.2.11.

--EDIT--

As it turns out, bridging is not an option. This is Hyper-V Server, so there's no GUI. Ref. here: "Network Bridge can be set up or removed only through Network Connections."

Solution 1:

• Connect the first NIC of the server to the gigabit switch.
• Connect the NAS to the gigabit switch.
• Connect the 10/100 switch to the gigabit switch.

Solution 2:

For software only options, I see two alternatives.

1) Add a vswitch attached to the second NIC of the Hyper-V host. Add a second NIC to the VM's that need access to the NAS. This second NIC (and the NAS) must be on a separate subnet from the first NIC/vswitch.

2) Add a vswitch attached to the second NIC of the Hyper-V host. Add another VM with 2 NICs, each connected to the two vswitches. Install something in that VM to do routing. This could be a linux VM, or Windows running RRAS.

(I don't think Hyper-V Server supports RRAS, but if it does, that is a third option.)