Need help setting up multiple PC's connected through two different networks

[HunterAP]

I'll try to explain my layout as best as possible.

• PC 1: Personal Desktop using Windows 10
• PC 2: FreeNAS Server
• PC 3: Ubuntu Machine

Each one of these machines is using their integrated Gigabit RJ45 NIC's to connect to a small switch I have connected to my router.

Also, each of these machines has a 10Gbps SFP+ NIC connected into a MikroTik switch (CRS305-1G-4S+IN) 4 SFP+ ports and 1 gigabit RJ45 port.

To better show it, I made a chart of how it's currently set up:

So here's where the problem lies:

1. FreeNAS does not allow for multiple NIC's to be registered as different IP's. I read one post from the FreeNAS forums that says you can't have multiple network interfaces connect through the same subnet/netmask. This is, I manually configured both the RJ45 and SFP+ NIC's to be on different subnets, but I can't connect to the FreeNAS machine from either of my other machines. Doing on a ping on either machine to the FreeNAS one results in a message 

   From XXX.XXX.XXX.XXX Destination Host Unreachable

   Which from what I've read means that my router knows that IP is registered inside my home network, but it can't find a way to get to that IP. Even when I remove the gigabit network interface and only have the SFP+ one, my other machines report the same issue.
   Also just want to be clear that this issue isn't present when doing actions to/from my desktop and the Ubuntu machine, FreeNAS is the only problem there.

2. How would I go about binding the different connections between my machines? Say I want to copy a file from my desktop to a FreeNAS machine: I want it to only use the SFP+ connection through the SFP+ switch, but right now it defaults to using the gigabit connection through the gigabit switch. For FreeNAS, I tried binding the SMB service for network drive sharing to the one on my SFP+ NIC, but it doesn't work and teh drives get disconnected.
   I'm also assuming that whatever sort of solution for this question would also help solve issue #1, or at least I'd hope so.

[Spakes]

Might be a longshot, but... Can RJ-45 switch create multiple local networks with only one port as the output (aka isolate all clients so they couldn't be seen in local network group of RJ-45) like OpenWRT can do? https://forum.openwrt.org/t/client-isolation/13914

If yes, try it.

[Lukyp]

What is the need for using a different subnet, if I could ask? Couldn't you just bridge those interfaces?

EDIT: Sorry, I didn't read carefully, but anyway couldn't bridging those two interfaces be the solution? Or maybe set those 3 on a different network (as long those 3 devices are the only present on the entire network, otherwise I suppose you have to configure the routes on the ISP router which is set as the default gateway) 

[HunterAP]

Ended up finding the solution online. My initial google searches were saying that you couldn't have multiple interface on FreeBSD / FreeNAS using the same subnet, but that apparently isn't true.

By manually setting the IP addresses of all my RJ45 connections to 192.168.1.XXX while having all the SFP+ connections use IP addresses 192.168.2.XXX, I'm not able to have the correct configuration for all my networking gear. Now I just wish the internet made it easier to find this information.