Firewalls are an integral part of a total security system. Every server ideally should have a firewall. But, firewalls do have limitations. They are frequently misconfigured and do not alert the administrator of intrusions or stop security breaches. Firewalls do not monitor internal abuse even if configured properly.
Organizations are dynamic and their people, software, and networks all constantly change.
Unless you are constantly monitoring for intrusions, you cannot know if your firewall is functioning properly. As such, the KSM is a vital tool to monitor your network seven days per week 24 hours per day. My company has an Intranet. Most security studies show that internal security breaches are as common as external threats. In most cases, internal servers contain much more important corporate information than the external sites placed on the World Wide Web.