Need Help to Configure NAT as well as No-NAT

[shaerul]

            Internet (Public)                 [Public IP from ISP]
                       +-------------------+|End User Workstation/PC|
                       |
                       |
                       |
                       |
                       | WAN [public IP x.x.30.132]
            +-------------------------------+
            |       OPNsense Firewall       |
            +-------------------------------+
              | LAN1 (private IP)         | LAN2 (public IP) 
              | [192.168.1.1/24]          | [x.x.31.1/24]
              |                           |
              |                           |
              |                           |
              |                           |
              + [192.168.1.10]            |
          |Server|                        |
                                          |
                                          |
                                          + [x.x.31.17]
                                       |Server|

As shown in the diagram, My OPNSense firewall has got three interfaces and NAT enabled. I want the NAT between WAN (public IP) and LAN1 (private IP) but don't want any NAT between WAN and LAN2 (just like a router) which already has public IP block x.x.31.1/24. ISP is routing all traffic to destination IP block x.x.31.0/24 through my WAN IP Address x.x.30.132.

I can make the NAT thing work flawlessly but cannot make no NAT or without NAT packet flow between WAN and LAN2.

Can anyone please help me to get this solved?

[chicken]

Did you ever figured this out?  I have the exact same setup and got it partially working but traffic sourced from the LAN2 segment gets natted but traffic that originates from the internet to LAN2 does not.  Thanks