@cfbcfb said in Wan not coming up, fresh install.:

Connected to the router via wifi and my phone, got a "this network wants you to sign in" and when I clicked that, it brought up the comcast login

That's your OS / brower playing the captive portal detection mode !
That means your WAN is using a RFC1918 IP, and when you start your bowser it hits the GUI web server of the modem, because it's router part is redirecting the browser requests to it's internal Web GUI, where you have to login.

What about playing with these option on the WAN interface :

37b478df-9583-49cc-9cf0-9fd448fc633f-image.png

See manual - Advanced Configuration.

It looks like you have something configured using 192.168/16 somewhere that is conflicting. It's not in the routing table though.
I would open your config file and search it for 192.168 and see what pops out at this point. There will be a lot of entries since you're using that for LAN.

Steve