I had a forced modem upgrade with them earlier this year. I vaguely recall it was not without some frustration, but I managed to get it done.

I don’t seem to have a problem logging in at 
https://login.xfinity.com/login
Is it transient or still persisting for you?


On Tue, Oct 10, 2023 at 5:07 PM Delong.com via NANOG <nanog@nanog.org> wrote:
I didn’t have a problem with it a couple of months ago, but that was when I installed Comcast Business, so likely a different user experience from residential. I had to call them on the phone to turn off my residential after the business install was completed and operational.

Owen


> On Oct 10, 2023, at 15:26, William Herrin <bill@herrin.us> wrote:
>
> Howdy,
>
> Wondering if any of the folks from Xfinity have tried activating
> internet service with their own modem and without installing a mobile
> phone app any time in the recent past. It doesn't work. It just
> doesn't work.
>
> http://www.xfinity.net/activate  ->
> https://idm.xfinity.com/myaccount/account-selector?execution=e4s1  ->
> https://login.xfinity.com/login
>
> Access Denied
> You don't have permission to access "http://login.xfinity.com/login?"
> on this server.
>
> Regards,
> Bill Herrin
>
> --
> William Herrin
> bill@herrin.us
> https://bill.herrin.us/