Talk between interfaces

[Chewbr0ca]

WAN1 - Public IP
LAN - 192.168.90.0/24
OPT1 - 172.168.89.0/30

There is a server on LAN1 (192.168.90.30) that I want a proxy server (172.168.89.5) on OPT1 LAN to communicate with. I am not an advanced pfSense user, but I have used it here and there from time to time.

In a nutshell (even at the simplest) –- how do I get OPT1 proxy to talk with LAN server? Or How do I get machines on LAN1 to talk with machines on OPT1 --- if I can get this I can narrow isolate it to just the two machines I need.

The firewall rules I had on LAN were
Interface: LAN
Address Family: IP4
protocol: any
source: LAN net
destination: OPT1 net

The firewall rules I had on OPT1 were
Interface: OPT1
Address Family: IP4
protocol: any
source: OPT1 net
destination: LAN net

Did I do this right? I was unable to even ping or access a share from either server.

[KOM]

LAN already has an Allow Any rule so your rule to allow to OPT1 is unnecessary.  I'm thinking your issue is local firewalls, not pfSense.  For example, Windows will block traffic out of its own subnet, so your 172.16.x.x traffic will be blocked by a Winbox on the 192.168.x.x network.