Configuring an Internet Connection Firewall
Figure 24.1 illustrates three different ways you might use ICF:
With a standalone dial-up or broadband connection (computer A)
With a shared dial-up connection (computers B and C)
With a shared broadband connection (computers D and E)
Figure 24.1. Shown are three common ways you might connect to the Internet. ICF is used on the connections that go directly to the distrusted network.
In each case, ICF is enabled only on the connection that attaches to the distrusted network. It is not enabled on the connections for inside the network because it would block the computers' ability to interact with each other ...