Cannot someone explain this strange behaviour to me?

Question

I have port1 and port4 bridged and assigned it the ip of 192.168.10.252 
 Port3 is not part of the bridge and has ip 192.168.10.253 
 
 The firewall is at the moment connected to the switch on port4. 
 
 I can reach both(!) 192.168.10.252 and 192.168.10.253 from my webbrowser. 
 
 How is it possible that I can reach 192.168.10.253, which is assigned to port3 and is not connected to the switch??

LuCar Toni · Accepted Answer

The point is, this will cause some kind of hell in routing scenario. 
 https://serverfault.com/questions/415304/multiple-physical-interfaces-with-ips-on-the-same-subnet

rfcat_vk · Answer

Hi. 
 you cannot have two LAN interfaces that are not in a bridge on the same network. That is why you can reach it. 
 Ian