I have some devices that don't have firewall neither can't have, it's like an arduino, more specifically its a esp8266 with "ESP-Easy" Firmware. And what i want/need is to only a certain computer be able to access it. like this:
1# ESP8266 board with ip 192.168.1.102
2# Computer with ip 192.168.1.100
3# Any other Device with a unknown IP address
2# is abble to communicate with 1# and vice versa
3# is able to commumnicate with 2# but NOT with 1#
How can i archieve that if 1# have no firewall. I thought how about my router firewall that have OpenWrt installed... but how?
What's type of rule i need or what rules i need