Connecting router (SMCWBR14S-3N) to modem (SB6121)

cable-modemdhcpmodemrouter

We recently purchased a Motorola SURFboard SB6121 modem and activated it with Comcast. After the technician activated the modem, she instructed me to connect a computer to it and try to go online. This failed, so she gave me a number for Motorola and told me to call back if I had any more problems. It turns out that the computer I was using (my mom's) never had Ethernet adapter drivers installed, go figure. How she manages to live without Ethernet drivers is an entirely different subject. I connected the modem to my computer and performed a power cycle. This worked, now I have internet (1 Gbps!). When I connected the modem to our router, an SMC SMCWBR15S-3N and performed a power cycle, the router never connected to the modem. I have reset my router to factory defaults, power cycled, and tried to connected again. I have tried setting a static IP for the router (the modem says it allocates IP addresses using DHCP, but it was worth a try). I have logged on to the modem's settings page, but there's really nothing there to change. I have tried everything I know but I still can't get internet through my modem. I have even tried a different router (old Linksys, I can get the model if you think that might help) to no avail. Please help me, preferably soon before my dad comes home and decides to fix it himself (he's largely computer illiterate, with the exception of excellent spreadsheet skills, so this would be a bad thing).

EDIT:
Light flashes blue when connected successfully to computer.
Light flashes amber when connected unsuccessfully to modem, but documentation states that this is an indication of a slower connection, not an error.

I am now going to try updating my router firmware. In addition, I will see if changing the power cycle order (router on first, then modem) will help.

Best Answer

Apparently, boot order is critical. I powered on my router first, waited 30 seconds, THEN powered on the modem. Now I have internet through my router again. I'm still curious as to why this might be, since all instructions I read say to do the reverse. Perhaps somebody has an answer to that, if not, I'll mark this as the answer as soon as the time limit passes.