4. What are the connections to the external networks?—
Although this is actually a part of step 1 and is determined
by a study of the network diagram, it is an important step
and should be dealt with separately. At a minimum level,
every network today is connected to the Internet through an
Internet service provider. The primary reason for connecting
to the Internet is to enable receipt and dispatch of mail and
to enable browsing by employees. Enterprises may also have
other reasons to connect to the Internet, such as e-commerce
web sites through which the company’s vendors, customers
and partners collaborate, place orders or exchange other
information. Dedicated connections to the networks of other
partners may also exist. The gateways through which each
of these connections is made are potential entry points for
the external world