UPDATE: Total failure. The new router won't connect to the Internet. I configured everything, everything about the router works, EXCEPT connecting me to the Internet.
It even says "WAN Connected", with my proper IP address, and "Internet: Connected". Except -- it doesn't work. No connectivity to the Internet at all.
I tried everything. My ISP is closed for today; they promised to call me back, and literally lied to me (they didn't call me back, even after 1.5 hours).
So I had no choice but to put my tail between my legs, and re-connect the old router. Everything came back up within SECONDS.
Ugh.
I DO NOT enjoy my server being down this long. In case you couldn't tell.
I'll try again tomorrow. I've had it for today.