Modem admin address while in bridge mode
Software engineer here with strong network admin skills.
I have always run XFinity in bridge mode, with a Linux-based router/firewall between my LAN and the modem, and this has worked well.
I recently noticed I can no longer access the modem's admin page at 10.0.0.1. This used to work as recently as last month but now it appears the modem in bridge mode is no longer responding to SYN packets on port 80 or 443 and I get "Connection timed out".
I've also tried connecting to the modem's external address, with the same (non-)result. In the past I could ping 10.0.0.1, but no longer.
nmap -Pn 10.0.0.1
fails to find any open ports, and I even tried
route add -host 10.0.0.1 gw [modem external address] dev enp3s0
with similar (non-) result.
The online Xfi management page just says the modem is in bridge mode and can't be managed there, and the XFinity app doesn't list the modem at all after switching to bridge mode.
Has Comcast changed the way you get to the modem's setup page in bridge mode? What's the magic incantation?