I'm happy now...got the router working [sort of]. My browser finally let me access the router address once, for some reason, so I could change the default address, and then it was clear sailing. However, I couldn't access the net in router mode, got 'not available offline' messages for configuration pages, and could get no connection. Ended up wiring the router as a switch [already a router built into the DW 6000, anyway] using just two LAN ports [ie- Wan port empty] , disabled the UPnP and DCHP functions in the router, did the rest of the configuration by the book, and all seems well. Setup as a switch will suit my needs just fine, anyway.
Wish I could specify how I got browser to access dlink pages, but have no idea, a lot of fumbling around in the dark, probably a combo of hehimself3's suggestions and dlink manual. Not exactly user-friendly, but then I'm not exactly a friendly user.
Thanks all, for your time, trouble, and suggestions.