How to forward a port from one network to another in Mikrotik Router OS and so that the real IP of the machine that sent the packet was visible, and not the IP of the gateway?

Question

Mikrotik

The point is. There is a gateway on Router OS. 192.168.5.5
Port forwarding of UDP port 45450 to 10,10,100,30 port UDP 514
is configured. There is a logging server that listens on UDP port 514. IP - 10.10.100.30
There is a D-link DES-3200-10 - the gateway is not specified on it and it is not necessary to specify it. It has syslog output configured on port 45450. IP - 10.90.90.90
There is Ubiquiti NanoStation 5 - it has a gateway specified and specifying it is required. it has syslog output configured on port 45450. IP - 192.168.33.20
Here's the problem. On D-link the gateway is not specified. The logging machine catches the packets and happily writes them on behalf of 10,90,90,90. on NanoStation - the gateway is specified and the logging server catches the IP of the gateway and records them on behalf of the gateway.
The point is. How can I make the real IP of the device that passes through the gateway shine?

Answer 1

The term "port forwarding" means the use of nat or pat technology, in which case the recipient of the ip packet has no way to know the sender's address because it is spoofed on the edge device (see the description of nat / pat). The exception is high-level protocols like http which contain the client's address in the data field of the ip packet.
If you are using the term "forward" in a different context, please define it. Better yet, provide a network diagram.