It is essential to know the source IP address of a packet to prevent the IP spoofing attack which masquerades the sender's true identity. If there is a way to trace back the origin of the massive DDoS attacks, we could find the responsible parties of the incidents and prevent future attacks by blocking them. Unfortunately, the original TCP/IP stacks don't require the real source IP address to forward the packets to the destination. Malicious attackers can modify the source IP address to hide its true identity and able to send the fraudulent packets to the victim. One of the critical features of the next generation Internet is having a secure Internet which provides trust between participants and protects the privacy of the individuals. In this paper, we review the various approach to provide the source address validation (SAV) schemes. There are many new methods have been proposed, no single way is providing the comprehensive solution to this issue. Privacy is a critical issue to consider when the true identity is available on the network as well.