Comcast XFINITY → Comcast HSI Structured Wiring - Router Needed?

My father has his comcast modem hooked into a hub/switch and it doesnt seem to work and Im wondering if thats becuase comcast wants him to pay for the extra ips or maybe the internets not working correctly. So my question is with comcast as your ISP should you run a router into your hub for structured wiring with cable and if YES can you please give me a link to an article that talks about structured wiring with Comcast or Cable as my ISP? I tried to google and didn't find anything.

when I reset the modem and then I plugged it into my laptop everything worked fine but then when i plugged it into the hub/switch the other end didnt work in the wall in the room, no signal.

The issue here is when you use a simple dumb hub or switch, each system connected to that hub/switch is exposed to the cable modem directly and unless you pay extra each month, you can only have one MAC address visible to the modem at a time. The solution is to use a router INSTEAD OF a hub/switch. A router exposes only one MAC address to the modem, no matter how many systems or other ethernet devices are connected to its LAN ports.

A little side note, if you ever change the device connected to the modem, you must also power down the modem so you can flush its internal MAC table. By default that table size is limited to one (hence the one device restriction), and the only way to flush the table to add a new entry is to power cycle the modem. Also note that some modems are built to withstand minor power fluctuations and some even have internal batteries now for VoIP service even in power outages, so you may have to do more than simply power cycle the modem, depending on what model you have.

this is a little network I put together for 15 computer / phone / cable connections. we ran it to a 4 port router first then to a 24 port linksys switch. its been good to him for a year or so now. as said you need a router first then to your switch.

great job on your little network box, looks great!

briankelly:

How did you mount that linksys switch?

I have a similiar setup, although its a mess at this point, I intend to clean it up very soon.

i took the cover off its just a few screws , but a few self tapping screws into the box and put the cover back on...

I said the same thing about 5 years ago

I'm not sure I follow. You took the cover off the switch and put self tapping screws through the bottom of its case? Isn't there a PCB in the way?

I have a 14 port gigabit switch...not sure I want to take it apart and start drilling through the case.

if i rememeber correctly there were only like 5-6 screws that held the cover to that switch on. i took that off and then was a board and some other stuff in there , i didnt touch any of that but there were a few spots were you could get to the bottom metal of the case and i just drill a few holes and used drywall screws. and then put the cover back on. i should have taken a few pics with the cover off but its simple it took like 20 minutes to mount that. I always use a 5/8 piece of plywood behind the leviton box, that way mounting anything, anywhere in the box is easy.

Hrmm...ok.

I have a leviton box too, but the builder did not mount it on plywood...it's attached to the concrete of my basement somehow.

I need to find a way to mount my switch, but I'm not sure how. I need a large switch, like you have, but I don't have room inside the leviton box.

I'll probably need to make some sort of shelf above the box and just set the switch on top of the shelf and reroute all the wires.

I think it would be nice if there was a section for comcast home network wiring or maybe a sticky set up because I bet alot of people are going to be running wires in their homes and some good tips would be useful.