A firewall is critical to building secure firewall architecture. In this part one of a two part series on Firewalls and Firewall architecture IDS (Intrusion Detection Systems) can not actually detect hostile invaders but simply limits their access to your sensitive internal servers. Properly designed and deployed, a firewall operates as a shield around your network.
A firewall functions by acting on traffic based on its policy. A policy is comprised of a set of rules. A rule is an action taken on traffic that fit a certain criteria. A system that tries to identify attempts to hack or break into a computer system or to misuse it. IDSs may monitor packets passing over the network, monitor system files, monitor log files, or set up deception systems that attempt to trap hackers.
Computer systems have become more vulnerable to intrusions than ever. Intrusion Detection is a security technology that allows not only the detection of attacks, but also attempts to provide notification of new attacks unforeseen by other components. Intrusion detection is an important component of a security system, and it complements other security technologies.