In this chapter
In this chapter, we take a look at network security. The issues related to securing a network have changed dramatically over the last decade , particularly due to the fact that most LANs are now connected (in some way) to the Internet.
Network security was once a very company-centric pursuit. It revolved around securing resources and information on an isolated network. Security concerns had to do mainly with the assigned levels of user access to important network resources and protecting systems from virus attacks (often spread initially from computer to computer by an infected floppy disk).
Today, due to the fact that most networks are connected to the Internet and that many companies maintain a Web presence in the form of a Web site, network security now focuses on attacks from the outside. These attacks often take the form of direct attacks by hackers (or crackers as the hacking community prefers to refer to those who maliciously attack networks). A number of new products, such as proxy servers and firewalls, have evolved over the last few years to deal with these latest security threats. Let's take a look at some of the LAN-centric issues related to network security (such as user/administrator interaction) and then we can take a look at some of the tools that can be used to protect a network from outside attack.