Wireless LAN � Commonly known, as WLAN or Wi-Fi Network is the most popular method for networking these days. The reason for Wi-Fi�s increasing popularity is its convenience of usage, Low cost installations and increased productivity. IEEE 802.11 is the standard protocol used by Wi-Fi networks. Although Wi-Fi networks are very useful but since the early days of Wi-Fi, various flaws have been discovered. Popularity and discovery of number of security weaknesses in WLANs multiply with each other and generate huge amount of issues. Wireless networks receive high number of attacks therefore, security standards need to be upgraded vigilantly and discovered vulnerabilities need to be resolved. Despite this fact most administrators are resistant to upgrade and want to stick to conventional wireless standards. The problem for the network administrators is to know which vulnerabilities are present in their networks in order to shield against them. As new standards are released, new vulnerabilities are discovered therefore Wireless systems require strict security and needs to be tested for vulnerabilities from time-to-time. In an Internet article (Palmer, 2001 November, p.7) discusses one of the best ways to evaluate security risks would be to let computer security professionals attempt to break into their computer systems for testing purposes. Therefore it can be suggested, that by simulating different attacks on the Wi-Fi network we can identify vulnerabilities in a network. Hacking with the agreement of owners in order to test and improve security is known as ethical hacking.