Hi
I would like to share the internet connection in my small office. Let me explain.

Existing Configuration:
In the past I have used the following configuration.

internet connection ( DSL )
|
|
Switch ----->Computer ( xp pro )
| \
| \
| Computer ( XP pro )
|
Computer ( xp pro )

I guess the above method is called Internet connection sharing. The drawback in that method is the lack of centralized control of internet connection ( centralized management may be possible but i am not aware).

I have decided to go for domain controller for many reasons in my office. So, I have installed the windows2003 domain controller in a machine. That win2003 domain controller machine having two network card. Now, I want to share this connection with all the other machines in the LAN ( xp professional installed ). Let me give you the diagram.

Internet Connection (DSL)
|
|
|
NIC - 1
\
\
Win2003 Enterprise edition - Domain Controller
/
/
NIC - 2
|
|
Switch ( 8 port )
| \
| \
| Xp Professional
|
XP professional

I have connected as per the above diagram. In the network card that is connected with inernet I have given the following:
Ip Address: 192.168.1.3
255.255.255.0
Default Gateway: 192.168.1.1

I collected some preferred dns and alternate dns from ISP. And entered the same.

In the other network card, I manually entered a different Ip address like 192.168.1.4 and left the gateway and dns to empty. I given the ip address manually to other computers.

Now my problem is :
I am able to access internet in my domain controller machine. But other computers unable to connect with internet. What is the mistake I have done above.
I am not a network engineer. I am a developer, just started reading about network. I request you to help me to sort this out.
One guys told me that You cant share internet with a machine that is also having domain controller. I have referred Microsoft that suggest ICS. It seems ICS is a pre-defined thing. I like to get my hands dirty, so that I can learn.
Thanks in advance.
Velan.