Using Netgear router directly with CenturyLink ONT?

As it turns out, it was a CenturyLink issue - Their ONT wasn't working (the "Service" light had never illuminated), and once they swapped a new one in and activated it, I was able to connect with their router. With that accomplished, switching to the Nighthawk took the following changes (after plugging the Nighthawk directly into the ONT):

Under Basic->Internet

1) Set "Does your Internet connection require a login?" to "Yes"

2) In the "Login" and "Password" fields beneath, enter your PPPoE username and password, obtained in one of three ways:

  a) Log in to your CenturyLink router and find it in the router settings

  b) Contact CenturyLink support via chat

  c) Walk through the steps at http://connect.centurylink.com/, and in the process they will display your username/password. In my case, this version included the"@centurylink.net" domain at the end, (<username>@centurylink.net>), unlike what CenturyLink sent me via chat earlier, so I included the domain to be precise

3) "Connection Mode:" "Dial on Demand"

Don't forget to "Apply" your changes and then navigate to...

Under Advanced->Advanced Settings->VLAN / Bridge Settings

1) Enable VLAN / Bridge Setup: Check (to enable)

2) Choose "Enable VLAN Tagging", VLAN ID: 201, Priority: 0, Wired Ports: All, Wireless: All

When you hit "Apply", your router will reboot, and you should have a connection.

Thanks everyone for the help! I hope this saves someone else some time.