How can I prevent Internet access with Windows SBS?

Question: I use Windows Small Business Server 2003 Standard Edition. I configured two network adapters: one for the

Preventing Internet Access Internet Explorer security settings and controls I have an SBS 2003. How can I limit user access?

local domain and another to connect to an ISP. I use SMTP in Exchange to send email and a POP3 connector to retrieve them. I discovered that any clients in my domain who put IP Server as their gateway can access the Internet. How can I fix this problem and manage Internet access using SBS server? (Note: I have ISA 2006 to control the Internet in my domain.)

Jonathan Hassell's answer: It sounds like you have a bit of a problem on a couple of fronts:

1. Your users should not have permissions on their local machines to change network adapter information, including the gateway address.
2. You have an ISA Server rule problem that's allowing unsanctioned clients access to the Internet.
3. ISA Server 2006 is not supported on Small Business Server environments.

SBS is meant to be at the edge of your network. It's not meant to sit on your network and collect mail, which is probably where the "hole" allowing clients to access the Internet through the SBS box is residing.