IPSec over Heterogeneous IPv4 and IPv6 Networks: ISSUES AND IMPLEMENTATION

In the face of looming IPv4 address exhaustion and the slow pace of IPv4 to IPv6 migration, this work deploys the IPv4/IPv6 translation gateway as a mechanism to ensure most of IPv6 mission critical applications to continuously interoperate with legacy IPv4 nodes. However, the existence of translation gateway between two IPSec nodes from disparate address realms imposes some incompatibility issues due to the violation of TCP/UDP and IPSec intrinsic functionalities by the gateway. In this work, we study and explore the incompatibility issues of applying IPSec across the translation gateway and then propose a workable solution to implement end to end IPSec in heterogeneous IPv4 and IPv6 networks. Experimental results show that our mechanism is feasible to establish a successful IPSec connection across IPv4/IPv6 translation gateway. Moreover, the proposed mechanism provides automatic detection of IPv4/IPv6 translation gateway or Network Address Translation (NAT) gateway, so that it can be backward compatible with NAT-Traversal in homogeneous IPv4 networks.