2 computers 1 cable modem can i use both on same modem?

All you need is a router. The router acts like a splitter, letting you connect multiple computers to one modem. Your ISP may have some option where they'll lease you a router and come out to set it up. Often they call this home networking. If they don't, you can buy a router for under $50 at most any major electronics retailer.

Will comcast know that i have my computers using the same modem?

No, all they will know is that you have one device connected to the modem. They will not be able to tell what you have connected to the router.

thanks for all the info i will let you know how it all turns out  

hi, i want to do the same thing... i know that a router is the most simple solution, but i wonder if two other solutions would work:
1. my cable modem has 2 outputs: 1 ethernet and 1 usb. can i connect one computer to the usb and the other to ethernet without any problem using the internet?
2. is it possible to replace the router with a switch? (so ethernet cable comes out of the cable modem, goes into the switch and the 2 computers are connected to the switch... they have different IP adresses)
(my ISP is UPC)

1. No

2. If you ISP will allow you to connect multiple computers (hence multiple IP addresses) then this will work. About 99.978% of the time it won't work. Each computer will need a real IP address from your ISP to function in this manner. A private IP like 192.168.x.x won't work.

hi, i want to do the same thing... i know that a router is the most simple solution, but i wonder if two other solutions would work:
1. my cable modem has 2 outputs: 1 ethernet and 1 usb. can i connect one computer to the usb and the other to ethernet without any problem using the internet?
2. is it possible to replace the router with a switch? (so ethernet cable comes out of the cable modem, goes into the switch and the 2 computers are connected to the switch... they have different IP adresses)
(my ISP is UPC)


1) No. This will not work.

2) For home use purposes, a Router and Switch both built into the device. You need the router to provide "NAT" and "DHCP" services. This will help protect your PC to a small extent to being directly connected to your cable modem. Never use the cable/dsl modem to connect to the internet. It is too unsafe. The Router/Switch combos - some with firewalls - will protect you and you need it.

(Note for Observers - Please don't try to get over technical about my explanation. The terms and explanations are simplified)

So..... I got this call for tech support from a buddy. He was setting up a computer on DSL that he had built, and asked me how to set this thing up on USB. After a couple minutes I found out that they had hooked up TWO computers to one DSL modem, through the USB and Ether.

So I told him to get a router and smack these guys for doing something dumb.

But I was curious to get some input from others, and I find this on the freaking front page!
Are you guys hearing about this a lot?
I'm very worried that this is being done by manual-illiterate home computer users that don’t know/care about firewalls and compatibility. Then they call us and are like "fix my broadbands.. nerd"

BTW zenmaster, that is prolly the best "Note for Observers" I have ever seen on a forum. You saved yourself like three drive by e-thugings!!!!

Note: You can do both USB and Ethernet on some DSL modems. The Westell 6100 supports a simultaneous connection of both USB and ethernet.

Cool! I did not know that.

However, I still would never connect a PC directly to any Cable or DSL modem for normal use.

I would always want some type of Firewall/Router in between to provide NAT protection in the least.

Now you could have two different Firewall/Router's here which could be nice.

I'm not talking anything fancy like a PIX for home users.
Any of the off the shelf $50 router from Linksys, NetGear, etc

I wouldn't connect directly either, but the 6100 has a built in firewall, as several other DSL modem/gateways. I have a Westell 327W, which has wirelss, firewall, and 4 ethernet ports built into one device.

That's probably why you can connect using both USB and Ethernet. Since the modem is doing NAT for you, you don't have the same issue of two devices needing public IP addresses like you would with a normal modem that doesn't do any NAT.

Yes, I have an ActionTec DSL modem/router that has built-in ethernet and USB, both of which can be connected at the same time. So, it depends on the modem.

@ dean7, that's good to hear as I also have an ActionTec DSL modem.

What else do I need to use 2 PC's?

A KVM switch like this:
http://www.monoprice.com/products/product.asp?c_id=101&...

How does it switch between PC's automatically?

Can both PC's be running at once (like one encoding and me browsing and using Office on the other?)

Edit*
Will this also allow me to transfer files from PC to PC?

A KVM (Keyboard/Video/Mouse) switch allows you to switch between the PCs by hitting a keystroke (for KVMs with 2 PCs it's probably something like <home><home><DownArrow>). So, yes you can do something like encoding on one, then switch to the other and use Office.

But, transferring files between PCs is not done with a KVM. You need to setup some sort of networking between the PCs. You DSL modem/router might allow you to do this (my ActionTec does), but it's probably going to be pretty slow. If you want to transfer serious data between your PCs, your best bet is probably to get a router with a built-in switch. Something like this would work: http://www.newegg.com/Product/Product.asp?Item=N82E1683....

The bottom line is: you would plug the router in to your DSL modem, then plug your PCs into the network ports on the router. That way, your PCs will have a fast connection on the built-in switch, and they'll both connect to the DSL modem as well. Make sense?

Thanks for the info, dean7.

I understood what the KVM was for  

One thing I don't understand is what is the advantage of a router over just a switch?

1. Yes I use Usb connection and ethernet for 2 computers.
Although Usb is half the speed of ethernet.

I am attempting to do the same thing, however:

My modem has a switch connected to it and both my computers are then connected to the switch, only one computer is able to connect to the internet. I would like both to be able to connect so that my wife and I can both surf the web or download stuff if we desire.