A FIREWALL - A SECURE GATEWAY OF THE NETWORK

Computer security is a tough problem. Security on networked computers is much harder. If the machine is connected to a network, the situation is much complex. Firstly, many more entry points to the host than a simple login prompt must be protected. The mai ler, the networked file system, and the database servers are all likely sources of danger. Furthermore, the authentication used by some protocols may be inadequate. Nevertheless, they must be run, to provide adequate service to local users. Second, there a re now many more points from which an attack can be launched. Your computers may be safe, but you may have users who connect from other machines that are less secure. This connection - even if duly authorized and immune to direct attack - may nevertheless be the vehicle for a successful penetration of your machines, if the source of the connection has been compromised. The usual solution to all of these problems is a firewall: a barrier that restricts the free flow of data between the inside and the outside. Used properly, a firewall can provide a significant increase in computer security