Date Added: Mar 2012
In Computer Network number of security techniques provide security consolation but not up to optimal security extent. There are massive attacks and efficient viruses travel across the network which incapacitates computer system and default configuration of the operating system. Preceding techniques can capture anomalous activates and previous known attacks but unknown Security attacks have learned to survive in a high secure precinct, it must be noticed by every technical person that virus has an augmenting influence, so it is very difficult to detect unknown attacks at application layer on the run time. This paper analyzes some of the best well known Intrusion detection techniques and challenging number of attacks including unknown attacks.