[forgottenit]

I'm confused how to make my router (WNDR3700, firmware DD-WRT v3.0-r30880 std 11/14/16) talk to the modem.

I had all this set up perfectly fine on a different router with dd-wrt before, but unfortunately didn't make a note of the settings.

The modem seems to be working fine, it's in 'modem mode' which means you get one ethernet port working which connects to a router, which then does all the routery things. Or you just connect it directly to your laptop, which is what I'm doing right now.

I go to the router's configuration page and go to Basic Setup. Under WAN setup, I say automatic configuration (DHCP). That doesn't work. I try using static and the IP of the modem (192.168.100.1). That won't work either. I see a confusing load of settings everywhere. I'm sure this must be very obvious, but I can't work out what I'm missing. Can someone kindly lend a hand?

Many thanks.

[forgottenit]

Don't know why, but 30/30/30 reset of router solved it.