There is a device with an ip address of 172.31.1.122 that is connected to a switch (Scalance 8008) and the switch is connecte to a router (scalance s615 which I cannot configure and has ip of 172.31.1.254). I want to access the data in general through our 5G industrian network (it is not a public network and completely internal).
When I connect my laptops lan socket directly to the switch, I can ping the device and when I scan it with nmap the port 502 appears open.
I have connected a 5G router(MU Scalance 856-1) to a setup shown in the below diagram. The sim card of my router has an ip of 172.16.1.32, and in the router I have defined a port forwarding from 172.16.1.32:502 to 172.31.1.122:502.
In general I am sure that my configuration of port-forwarding is correct because I have done this before with a couple of other devices with the same 5G-router model.
However, when I scan this port with nmap (nmap 172.16.1.32 -p 502), it shows the port being filtered.
The problem is likely that the Sentron-Com shown in the diagram has a different gateway but I am not sure how to handle it since it is not something I can change.
Is there a way to make it work similar to when I direct my laptop directly to the switch beside the internal router?
There is also probably a possiblity using Source NAT but I am not sure how to configure it and what I should write in each field:
