Isolate Networks from each other and configurate it right

Hi there.
I hope there is someone that can help me cause I am rly brainf*ed…
What I am trying to do is, I have some Container that should be able to connect in an own network, and to be bridged direct to an “eth”(is in reality an VirtualSwitch on my QNAP NAS). OK… I have created a new bridged Network, assigned it to the Containers needed, and then asigned this VirtualSwitch to my pfSense on an VritualMachine (is not a docker container). Anyway this is not the problem… The problem is, that it does not matter how I configure it, they still are able to comunicate to each other in the docker networks (my own created network and the default docker0).


Thats what I am trying to do.
Why am I able to ping from Container1 to the Firefox4All Container?

Hope someone can help me to configurate it right…
I have read this Thread but its maybe a bit to complicated for me…
https://success.docker.com/article/Docker_Reference_Architecture-_Designing_Scalable,_Portable_Docker_Container_Networks