The Internet is expanding year by year and providing services of convenience and commercial value. It is also becoming prone for many attacks. Every day, new vulnerabilities are found, new threats are detected and attacks are launched. We need countermeasures for these attacks and IDS and firewalls are not able to defend all the attacks. In this situation we need to traceback the attacker and get to the source of the attacker so that there is deterrence to the cyber criminals, thereby reducing attack rate. In this paper we survey various traceback techniques for IPv6 after introducing the same for IPv4. We also analyze the differences between packet header fields of IPv4 and v6 and list the challenges for IPv6 traceback.