Howto for OPNsense as not-NAT firewall with public routed ips behind firewall

[icecoke]

Hi there,

after trying around a bit with OPNsense as simple firewall with a private-IP LAN, I wonder if there is a howto etc. for setting up OPNsense as a replacement of an cisco ASA for a small datacenter with public IPs behind the firewall. So no NAT but, what else should be set?

Any hint/link or something alike?
Many thanks in advance!