I'll have to call defeat...
I thought I knew enough about networking to convert the #Netgear #N300 to a Wireless AP connected to the new #Genexis #Platinum7840, but none of the usual setups that previously worked for me allow me to reach those connected to the Genexis router, nor the internet.
Given that the Netgear AP also isn't getting an IP address assigned from the Genexis' #DHCP server, my guess is that the latter either isn't working properly, or does some isolation Ive no control over.