MattOB's profile

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Wed, Oct 14, 2020 12:00 PM

Gigabit Internet not working properly - Modem Issue?

I recently upgraded my service to gigabit speed. But, when I go to swap out the modem (Motorola MB8600), I can only get internet on my ethernet connected pc. It will not work on my wireless router or any other ethernet ports on my gigabit lynksis switcher. I've tried  the Arris SBG8200, and Netgear CM1200, same issue. Xfinity sent a tech, and my signal is good, no issues. My current modem is Arris SBG6400, and everything works great, but I'm only getting 250 mbps (a fraction of what I'm paying for). I was wondering if anyone had any insight on this, it just doesn't make any sense to me. Below is an explanation of how my home network is setup.


Xfinity Coax main feed into Arris SBG6400 modem, which feeds ethernet to my linksys gigabit switch. The switch feeds 10 ethernet cables (cat6) througout different rooms in my house. My wifi router is connected to one of said ethernet lines which broadcasts a great signal. 


Any help is greatly appreciated!






Diamond Problem Solver


25.9K Messages

7 m ago

The first step is getting the proper modem and figuring that part out. The original modem isn’t rated for gig service but rated for the 250 that you’re getting. Maybe you should be troubleshooting with the modem and/or router manufacturers as it’s their equipment. You’ve proved your Internet “works”, that’s really where Comcast troubleshooting stops because it’s not their equipment

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