In the near future IPv6 is said to become the new version of internet protocol replacing IPv4 protocol. Other than providing huge populated address, IPv6 also provides
simplicity in configuration, routing speed, quality of services and more importantly improve the security mechanism. The deployment of IPv6 will not occur over night but it may take several years. Several methods have been found to be applied in the transition of IPv6 to IPv4 protocol. As IPv6 is not yet in full throttle there are possibilities of intrusion and computer threat especially during the transition period. This paper reviews
the security threats of an IPv4 and how it ’s going to effect the implementation of IPv6
