This paper is focusing on detection and prevention Sybil nodes in Wireless Sensor Networks. Sybil is a fake-ID based malicious activity destroying the networks behavior. Here IPTTA — [IP Traceback and Token Assigner] approach is proposed to detect and prevent Sybil attack by assigning and verifying IP address with assigned unique Token for each node in the route. IPTTA verify the node IP, Token with time stamp and fetch the contradictory node as Sybil node. The simulation results show that the IPTTA provides better result than the existing systems and reduces cost and time.