Firewall: Best practices to use chains ?

Hi Folks …

I am almost there with my setup. However - I’d like to hear from those of you who have it - how to proceed best with the following setup.

I have 4 Network Interface:
pppoe,wlan1,Bridge-Service,Bridge-vpn (Which is the LAN)

with associated subnets.
Now - I want to make sure - that traffic flowing through the RB153 can not jump from one interface/subnet to another one.
I have followed the first-art guides found on the wiki - but these do actually only protect the network from the external interface.
However - me comming from the Security side of Systems/Networks - I tend to want control on the traffic from all destinations to all destinations, forcing me to apply interface/subnet based policies.
So to my questions:

  1. Anyone has an example of the configuration I have in mind ? Even only for 3 Networks… I’ll adapt.
  2. In which default chain (input,forward,output) would you place:
    a. Interface based access policy
    b. Inter-interface network flow policies
  3. In which chain would you place the address-redirections ?

Thx for any hint …