Sorry, I'm really bad at explaining things, and I'm also confused with this.
I'm using this device (a banana pi r3):

The 4 ports marked as 4x GigE LAN are shown in ip addr as lan0@eth0 up to lan3@eth0. The GigE WAN/LAN port is shown as wan in the ip addr output. (I will post the full ip addr output soon, because I locked myself out from ssh access >.<)
The wan port is connected to my home router, and in the lan ports, I have 4 other devices connected. I want to have all devices connected to the banana pi lan ports available for accessing from any device connected from my home router. I also want the banana pi board to be accessible via ssh from some static ip