Here is the hypothetical:
I have two routers connecting to my individual wan links. I connect both of them into 1 switch. Then I connect the switch into a firewall. Then I connect the firewall into a switch which connects to my internal network. My lame attampt at a diagram is below:
Router 1 (DSL router) ==>Switch 1 ==>Firewall 1 ==>internal network 1
Router 2 (Cable router) ==>Switch 1 ==>Firewall 1==>internal Network 1
Lets say I have the firewall setup to send all requests through to "router1" (my firewall has a setting to define only 1 wan link). Now, I set up a windows XP client to use "router2" as a gateway. I have port 21 blocked at the firewall, both ways.
Will the firewall block the internal client's request for port 21 on the internet, even though the firewall is configured to use "router 1"? Will the firewall block requests for port 21 into my network that hit "router 2"?