Intrusion Detection Systems: A Review

Protection of computer resources and stored documents is an important issue in today’s world. Intruders have made many winning attempts to overthrow prestigious company networks. Although the current security solutions such as firewalls, and anti-virus software have their significant roles in securing organizations but they do not detect all types of attacks of today’s cyber world. Intrusion detection is a mechanism used to detect various attacks on a network. There are many Intrusion detection Systems (IDSs) available today. Some of them are open source while some are commercially used. In this paper we give a brief introduction to open source IDSs: SNORT and BRO. Some of the common types of attacks on various layers of TCP/IP and how SNORT and BRO handle these attacks are discussed. Current research in intrusion detection is also included. It is concluded that intrusion detection is a challenging task due to the advent of many unknown attacks.