I have the latest openwrt 18.06.1 installed on my avm 4020. The following behaviour I want to implement:
Route all incoming traffic, that means addressed to the routers ip, of the WAN side to one specific address on the LAN side. There will be just one device connected to LAN side. Of cause I want the same way back: Traffic from the LAN side should go outside of the WAN side using the ip of the router.
From outside it should look like communicating with a PC (which is located on the LAN side ) when using the routers wan ip address.
Routers IP address is 10.1.1.50, PCs IP address can be any IP also 10.1.1.x. A script has at the end to detect which PC is connected.
I tried a lot of SNAT and DNAT examples but I stucked always with having no access to the router at the end.
I am very unused with this topic and appreciate your help. At the moment I am using the LUCI interface, there custom firewall rules.