@johnpoz:
I don't get it?? Why would anyone set up something like that??
And you have multiple down stream routers for different segments as well? Is there anything below those routers? More routers? Oh so that is what you meant by gateways.. Why so many?? Where is the core of this network? So all your routers are running vyatta? On what hardware? Why would you not just put in a nice layer3 switch and be done?
So what pix, you mentioned a 515 you got rid of.. What are the existing ones? Why don't you just replace those all with 1 pfsense box? You can easy add multiple ports there. But I don't understand why you need so many segments? If you want the ext and internal - great that is 2 boxes ;) And then a L3 switch below there for your other segments. Sure set them up in HA if you want, etc. So say 4 boxes 2 ext, 2 internal and 2 L3 switches.
With the absense of Layer 3 switches would the following be possible? Likely to cause any issues?
Green and Orange represent data flow along different VLans (only drawn 2 I have 25 in use) on the internal network. Blue would be a Vlan on the external side for traffic between subnets and would be on a private address range, red would be vlan for internet bound traffic, with the interface being public ips
Black lines are the physical connections and would pretty much all be trunk connections.
Hopefully that all makes sense, and thank you for your input

