Do IPTABLE rules apply to other devices on a network?

Question

I have an embedded device that listens to a specific port to be programmed by vendor specific software. If I have a network that consists of a small linux computer and this industrial device would setting a rule that blocks access to the port block access to the industrial device as well?

Answer 1

Netfilter rules can only affect packets which are routed to or through the device. So unless the computer is "in front" of the device, no.