Local Area Network (LAN) based attacks are caused by compromised hosts in the LAN and mainly involve spoofing with falsified IP-MAC pairs. Since Address Resolution Protocol (ARP) is a stateless protocol such attacks are possible. Several schemes have been proposed in the literature to circumvent these attacks, however, these techniques either make IP-MAC pairing static, modify the existing ARP, patch operating systems of all the hosts etc. In this paper we propose a Discrete Event System (DES) approach for detecting ARP spoofing attacks. This approach does not require any extra constraint like static IP-MAC or changing the AR