Hi, sorry in advance for my lack of knowledge in this area.

I have a hAPlite router, and two other devices on the network, A and B:
hAPlite router: 192.168.133.1/22
device A: 192.168.133.160/22, port 2
device B: 192.168.100.1/24, port 3

I would like device A to be able to reach device B (via TCP).

I have tried under IP->Firewall->NAT to add a rule with the settings: srcnat (chain), src Address (192.168.133.160), action (src-nat) and To Addresses (192.168.100.102), along with numerous other configurations, however I have been unable to get any pingable response from device B.

All the router needs to do is mask device A's IP in packets going to device B, and device B's IP in packets going to device A. Seems like such a simple task to just replace some bytes in the header packets, but alas, I have gotten nowhere.

What steps do I need to take in the Mikrotik router to set this up correctly?

Thanks :)