This chapter gives a practical overview of the brief implementation details of the IEEE802.11 wireless LAN and the security vulnerabilities involved in such networks. Specifically, it discusses about the implementation of EAP authentication using RADIUS server with WEP encryption options. The chapter also touches on the ageing WEP and the cracking process, along with the current TKIP and CCMP mechanisms. War driving and other security attacks on wireless networks are also briefly covered. The chapter concludes with practical security recommendations that can keep intruders at bay. The authors hope that any reader would thus be well informed on the security vulnerabilities and the precautions that are associated with 802.11 wireless networks.