Xfinity is blocking Motorola MB8600 modem administrator/diagnostics screen

@EG

Well, leaving off :80 just defaults to :80.  It's the same thing

I've tried it both ways.

Regardless, I ran a port scanner.  Port 80 is blocked 

@EG

I tried that twice.  Performing a factory reset on the modem unblocks port 80 - but, then the first time the modem connects to Xfinity, Xfinity blocks port 80 again 

I overlooked that you wrote that, sorry. Hmmm..... It's a straight cable modem / layer 2 bridge. Not a router. It has no built-in port blocking function unless they are blocking it in the configuration file or the firmware load for some reason. I don't know what else to tell you..... All I know is that people access the UI pages and post the signal stats that I request here quite often with that model modem.

Good morning @tarn0ld. Thanks for reaching out to us regarding the inaccessible port, we appreciate your continued loyalty and being part of the Xfinity family. Are you able to reference the link my peer posted on the top to this thread to review the blocked internet ports list? 

XfinityGabby,

"The link my (XfinityGabby's) peer posted at the top of the thread" 

https://www.xfinity.com/support/articles/list-of-blocked-ports

Doesn't provide any useful information.  It looks like something you might set up on any firewall.

The list of articles at

https://www.xfinity.com/support/internet#get-started

Mostly stays away from the subject of modems and tends to confusingly blur when it is discussing modems and when it is discussing routers and when it is discussing gateways.

Previously to the problem being discussed here, modems would typically be running a flavor of Unix and had a web server running on them to provide a customer interface.  Usually, a lot of detailed information regarding the status of the ISP's network was provided and a log of network statistics.   All of that is running on my modem apparently - but, it is not available .

At this particular moment, http://192.168.100.1:8080/ does not respond and ports 80 and 443 are filtered.   Oh, well...

@XfinityGabby​ The blocked ports list has nothing to do with this.

Comcast / Xfinity, I SEE YOU, I WILL REPORT THIS TO THE FCC

@EG​ :

I gave up.  It is obvious that Xfinity modifies the modem the first time it connects to Xfinity.

You can re-set the modem to factory setting and access it as a normal modem - but, the first time it connects to Xfinity it is modified by Xfinity and you cannot access it.

I contacted Motorola - but, they were obviously avoiding answering any question and I guess I couldn't really expect for Motorola to explain to me why and how Xfinity modifies the modem.

It is a bazar situation.  I assume it's some Xfinity techies in the sub-basement of an Xfinity office doing things that others in Xfinity have no knowledge of.  It seems to be undocumented and unknown by anyone you might talk to who works at Xfinity.  Maybe I'll run into someone at Xfinity at a social function or industry conference or something and maybe talk them into doing a little investigation into this secret situation.

Sorry to hear that man.... 🙁 Good luck !