I’d love to see something like a definitive answer to this question:
Which of these 3 configurations of SBS 2003 is the “best practice”?
Assume that external access to the server is required for things like OWA and Remote Workplace
Option 1: SBS is the firewall and LAN internet gateway, directly connected to the internet via 2nd NIC
Option 2: SBS is the gateway (again via 2nd NIC) with a router or firewall appliance between it an the Internet
Option 3: SBS and client systems all use the router as the gateway/firewall; SBS has a single NIC
Option 3 is what we’ve been doing, but my feeling is the option 2 is probably the best. On the other hand, I remain concerned about the load on the server due to all LAN internet traffic passing through it. I have no idea whether that is a real issue or not.
This is a rather broad question I know, I'm looking for some definitive pro's and con's.