I figured it out: please ignore this post unless you are having similar problems. Answer in post 2. Just got Time Warner's "Wideband" (55MbpsDn/5Up), modem: "Motorola SURFboard Wireless Cable Modem Gateway". (WiFi on the modem off at my request). Short version: Works when I connect Ethernet to a Mac, Network: using DHCP. Does not work with my Airport Extreme, using the setting left over from my last attempt at Verizon DSL: Internet Connection (tab): Connect Using: Ethernet Connection Sharing: Off (Bridge Mode) TCP/IP (tab): Configure IPv4: DHCP Never picks up an address from DHCP. Maybe I simply never did the right dance with powering up/down Airport Extreme/Cable modem. Does anyone have a similar setup and can tell me what setting they are using on their Airport? Any and all help immeasurably appreciated! Time Warner's customer support was singularly unhelpful.