This is easy peasy via firewall rules.
Typically we have a last rule in our firewall forward chain that is a block all else rule.
Just before this rule we would make one that basically states.
Allow PC1 on network 1 to access PC2 on network 2.
What isnt clear to me though is if you want it as a one way connection or two way.
By that I mean can both initiate a connection (responses are always allowed) .
add action=accept chain=forward in-interface=network1 src-address=IPofPC1 out-interface=network2 dst-address=IPofPC2
Is the general idea.
By the way, I saw Rextended' house pictures, this is what it looked like.
Aka, some of us dont have the luxury of having our houses wired internally within the rooms (vice in the walls) ;-P
rextended.jpeg
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