Sorry for the confusing question. Our present setup is a cisco router as the default gateway for our network, then the firewall in virtual wire mode, then the core switch. We want to change from virtual wire to layer 3 with minimal disruption to our network. This virtual wire connection has been our primary internet connection, but we need to connect a second WAN connection that we need to transfer business processes to. That means layer 3 due to the need for the most options with policy based forwarding, NATting, etc. I know we can move the subinterface IPs from LAN side of the physical router to the LAN side (to the core switch) of what would be the layer 3 setup on the firewall, using some other private subnet between the virtual router on the firewall as the next hop from the virtual router to the cisco, and use RIP to advertise the routes from our LAN through the virtual router, to the cisco. I just don't have enough understanding if we can use additional local IP addresses from our current subnets so that they are on both sides of the layer 3 connection on the virtual router. Around here is where I get confused, since by defintion router break up networks / broadcast domains. I think in my head i'm confusing a layer 2 deployment with what is possible with a layer 3 deployment. I'm just trying to get the vwire converted to layer 3 without having to go to far into NAT rules, etc. I think the easiest thing to do will probably be to work with our ISP who is currently managing our router to plan out a simple RIP setup between what will be the new virutal router, and the cisco. We just need exisitng traffic flows to go to / from our LAN so we can begin mirating things over to another interface on the firewall (new isp connection, basically going to our own public address space from our ISP NATing what we need).
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