The development of IPv6 networks has reached the maturity for product deployment nowadays. Organizations often want to deploy an IPv6 dominant network, in which no IPv4 network devices need to be maintained, but the IPv6 nodes in such a network have the backward compatibility to communicate with other IPv4 networks. Many IPv4 to IPv6 transition mechanisms exist. However, they were not designed for IPv6 dominant networks. Dual Stack Transition Mechanism (DSTM) is an IPv4 to IPv6 transition mechanism that is specially designed for IPv6 dominant networks. However, its performance in real networks is unknown. The contribution of this paper is the analysis of the difference between DSTM and other transition mechanisms and the evaluation of DSTM’s performance, scalability, interoperability, and portability. Our analysis is based on two DSTM testbeds set up in the US and France respectively. The experiment results show that DSTM is a light-weight transition mechanism.