TABLE OF CONTENTS When most people think about Internet security, the first thing that comes to mind is a firewall, which is a necessity for connecting online. In it's simplest form, a firewall is a chokepoint from one network (usually an internal network) to another (usually the Internet). However, firewalls are also being used to create chokepoints between other networks in an enterprise environment. There are several different types of firewalls.
Before we delve into what types of firewalls there are, we must understand the present threats. While there are many types of threats, we only discuss a few of them in this chapter, paying the most attention to those that can be mitigated by firewalls.
Ensuring a physically secure network environment is the first step in controlling access to your network's data and system files; however, it is only part of a good security plan. This is truer today than in the past, because there are more ways into a network than there used to be. A medium- or large-sized network can have multiple Internet Service Providers (ISP's), virtual private network (VPN) servers, and various remote access avenues for mobile employees including Remote Desktop, browser-based file sharing and e-mail access, mobile phones, and Personal Digital Assistants (Pads).
One of the most important and overlooked aspects of a comprehensive network security plan is physical access control. This matter is usually left up to facilities managers and plant security departments, or outsourced to security guard...
