Basic Internet Connectivity And Modem Help

[CaptainWow]

So after spending far longer than I'd like on tech support calls, I finally got the internet working at my new apartment. Problem is, I can only connect one device at a time. If I've got the Xbox on, my laptop can't get internet access, and if the laptop is on the xbox can't get assigned an IP address from the router/modem. The Comcast techs seem to be clueless as to what I'm dealing with. I'm using nearly the same setup as I was using at my parents' house but now it's not working. For some reason. How can I get internet on my laptop and two xboxes at the same time?

SB5101 Motorola SurfBoard modem

linksys 5-port ethernet hub

NO wireless capabilities,  everything is through ethernet cables.

[EG]

You can't use an ethernet hub or switch with Comcast. They normally only issue one IP address for residential service. You need to use a home networking router instead.

[CaptainWow]

Ah, but you see, I was with Comcast at the parents' house, using the same setup but with a different modem. Worked beautifully.

[EG]

Do they pay Comcast for additional IP addresses ? Because that would be the only way it could work... Perhaps the hub was connected to a router or a combo modem / router gateway device and being used as an ethernet port expander ?

What is the exact model number of that device ?

[CaptainWow]

that is possible. But wouldn't one of the Comcast techs have said something to that effect one of the multiple times I've called them about this?

[CaptainWow]

to which device are you referring?

[EG]

The Linksys.

[CaptainWow]

The hub? it's a Fast Ethernet 10/100 network hub, model number NH1005, version 2.0

[EG]

Yep. That's a hub. Just checking. Some people mistakenly call hubs and switches routers and vice versa.

It won't work connected directly to a cable modem unless you have additional public IP addys from Comcast. Only one LAN client at a time will work.

[CaptainWow]

so is there any way to bypass this without upgrading my service?

[EG · Accepted solution]

As stated, get a router. It will be cheaper in the long run. In some areas Comcast doesn't even issue additional IP's anymore.

[CaptainWow]

and is there anything special the router needs to be able to do? ....I'm new to the whole networking thing.

[EG]

No, nothing special. Any ordinary home networking router will do what you need it to do. It's beyond the scope of these forums to give a tutorial on home networking, sorry. Perhaps you could Google for that info.

[CaptainWow]

I appreciate your time unbelievably super muchly. Thank you!

[EG]

Good luck !