Hi, I just suscribed with a cable company and I am using a motorola cable modem sb5100. I had dsl previously, and had a home network. To access my dsl modem I just had to type in its IP address on a web browser. But with motorola cable modem it is different. I tried hooking up a home network but I cant access the internet from the other computers. I am totally lost here. I looked at the manual that it comes with, but it really doesn't help much. Apparently it only supports dhcp also. Anyways, can anyone please help me.

What distribution / version of linux are you running?
I assume your using ethernet and not the USB connection?
What is the configuration of your home network?

Yes, all you need to do is configure the ethernet adapter for DHCP. But...

How are you connecting your home network to the modem? Do you have a router?
It depends on what type of service you subscribed to but typical basic broadband cable only provides one dynamic IP address.

The ip address of you modem is 192.168.100.1, but there is not much you can set.

Also, what is between you modem and the two computers, as there must be something? router... hub... switch... something.

From motorala page:

Meaning if you want to have a LAN you have to pay for more IP's from your cable provider and get a switch/hub. You would be stupid to go with that option though.

Better to buy a router and then you can have as many computers on your LAN without paying more money, and the router will be a NAT firewall as well. Most are very configurable when it comes to seting up ports and protocols to allow through or block. Some come with SPI (state full packet inspection) ... drop DOS attacks and stuff. Or you could set up a linux box to be the a gateway/router/firewall/DHCP, but that will require that box to be on 24/7 to provide this services to you LAN.

I have a switch on my network. All my computers are connected to the switch, and the cable modem also. I am using SuSe Linux and Windows Machines in the network. The switch is a very simple switch. Its brand is Octupus. It worked very well before when I used DSL.

Unless you have more than 1 IP coming in, the switch anit going to do jack. You are going to need a router to break up the IP's. Do you know anything about networking? Do you know the difference between a switch, hub, and router? Do you know what a gateway is or what a DHCP server is?

It depends on your service but it is typical that basic DSL provides 3 dynamic IP addresses and cable only 1. So you will need to either purchase a hardware router or another ethernet adapter and use your linux PC as a router or get additional IPs from your ISP.

The cable modem saves the ethernet adapters MAC so be sure to reset power to it prior to turning on the PC or router. You should be able to connect any single PC with your current configuration.

A router/firewall whether a PC or a hardware unit provides additional security by isolating your network from the rest of the internet.

Yes chbin, I would say I know a thing or two about networking. It is the first time I am working with cable modem, and I am not familiar with it. I was assuming it worked the same way DSL works. I didnt know if it was the type of modem or if it was my internet provider or if I was missing something. Thanks to micahelk I have a good idea now of what it is I am facing and what I need to do. I didn't know cable only provides 1 dynamic IP address and that the cable modem saves the MAC address. I googled for this type of cable modem but I didnt get jack. Just the typical marketting stuff, nothing technical about it.

Anyways, thanks guys, you have been alot of help.