Just want to make sure before telling a customer to purchase this firewall. Basically this customer uses about 15 subnets (over the course of a couple years has gradually grown needing more and more IPs). But some of his servers, for various reasons, aren't on the same subnet as another server and so when transferring traffic it goes through to my router. My router contains it all in their vlan, but appears to still count it as traffic for them. It's not so simple as it seems for them to change their servers' IPs, so they want to put a firewall in between their switch and my router that does basic static routing. That way the inter-subnet routing is handled by their firewall and my router only gets traffic destined for other networks. They are assured I'm not counting more traffic than they're really using and they get firewall protection.
So I would just assign the PIX a /30 like I would any customer's router and route their subnets to it. Nothing would change on the servers (a critical requirement). They would have the same public IPs and the same gateway. Although they might need to clear their arp caches on their servers as the gateway is now their firewall instead of my router.
Even better would be if the PIX 515E supported ospf in this manner.
