Keep your users happy. And those products were relatively primitive. Today there is a sophisticated blend of protective devices that organizations can throw into their security mix. There are three types of firewall technologies available, with different strengths and weaknesses. They can put a blanket block on traffic coming into the network or block connections to and from specific hosts.
Proxy servers examine network traffic according to policies set for specific applications.
Stateful inspection firewalls examine the data packet itself and look at all the layers of a network to make sure they comply with a security policy. Intrusion-Detection Systems IDSes are used to detect unusual or unauthorized activity in a network of computer systems. When an intrusion is detected, the IDS can react in a number of ways, from simply alerting systems administrators to the intrusion and letting them decide what action to take, to automatically kicking the intruder off the network. Network-based systems use monitors placed at strategic points on the network to examine data packets in order to determine if those data packets conform to known attack signatures. Host-based systems use intelligent agents that constantly monitor computer audit logs for suspicious activity.