WEP and WPA are the two main security protocols used in Wi-Fi LAN. These vulnerabilities exist because of issues in WEP or WPA. Poor encryption is related to security keys used to protect the wireless network. It may include a weak password, a lack of security settings, use of default configurations and other user-related issues. Poor configuration is caused by the network admin who manages the network. One is poor configuration and the other is poor encryption. Two types of vulnerabilities can be found in the Wireless LAN. But in ad hoc networks, there is no access point each node connects in a peer-to-peer way. Infrastructure networks have one or more access points that coordinate the traffic between the nodes. Wireless networks are based on IEEE 802.11 standards defined by the Institute of Electrical and Electronics Engineers (IEEE ) for ad hoc networks or infrastructure networks.