Internal IP to WAN

[d2co]

Sorry my English didn't strong.

LAN 172.x.x.x
WAN 20.x.x.x

When clients get in to pfsense and pass I want it have same ip.
Ex. Client 1 172.0.0.11 pass pfsense and pfsense send this ip to external.

How to do this?

Thank you.

[phil.davis]

Normally pfSense will do NAT out the WAN, so traffic going out WAN will appear to come from the WAN IP.
When WAN is on the public internet, and LAN is private address space, like in your example, you have to do that. Because the public internet cannot route back to your private address space.
If you have public IPs on LAN, then you could switch to manual outbound NAT and delete all the rules. That will send packets out from LAN clients with the real LAN client IP as the source IP.

Why do you think you need to do this?