Corbeau wrote:VivienM, I think it can, but you're right, that would be an ugly solution. I can give it a shot and see if it works but I would like to avoid that if at all possible.
Hopefully my company will install the line for me here at home so that I have a second IP address (really don't understand why Rogers doesn't offer secondary IPs for residential customers anymore) and I can build this network off of that one. That would make this a lot easier!
Thanks for all the responses, it looks like the SMCD3GN just doesn't offer what I need. Which is surprising considering all it does offer.
A second IP wouldn't help with this by itself. You'd also need another router to handle the NAT of the non-891 network, since the SMC would need to be in bridge mode. (And I think this is why Rogers doesn't offer second IPs anymore, now that no one has straight modems, the use case is extremely narrow)
Honestly, I think you're being unfair to the SMC here. What you're trying to do is an extremely unusual set up, one that I would not expect consumer-grade NAT hardware to handle nicely. Handling your situation nicely calls for something serious as a router, i.e. a 3-interface x86 box running real software, not some glorified appliance. (And yes, I understand, that seems like overkill for a temporary situation. Then the temporary solution is to turn on NAT on the 891 and put up with the limitations of that)
(P.S. If you do have a second NAT router handy, put the SMC in bridge mode and try it out. I think Rogers DHCP will hand out a second IP... or at least it did when I briefly tried plugging in a laptop directly to the second port of my bridged CGN3)