The exhaustion of IPv4 addresses has forced the deployment of the new version of the Internet Protocol (IPv6). However, the migration to the new protocol is done gradually and with the due care for many reasons that include: cost, inclusion of support for IPv6 in existing applications, training of technical staff, lack of web content available over IPv6 from important providers, and obsolete devices not anymore supported by manufacturers. For those reasons, many transition mechanisms have been proposed, each one to fill distinct requirements, with different operational theory and availability according to the network environment. A performance evaluation of these mechanisms can help network administrators and researchers in their selection of the best transition technology for their environment. In this paper, we present a performance comparison of some transition mechanisms such as ISATAP, 6to4, and NAT64 in real testbeds with Debian, Windows 7, Windows 8, and Windows 10. For NAT64, two different tools were tested: TAYGA and Jool. We measure the OWD and the throughput for UDP and TCP for every mechanism, for both Ethernet and Fast Ethernet technologies. From this research, we can conclude that all the modern operating systems for PCs already have good support for IPv6, and a very similar network performance. Also, we can infer from our work that in controlled environments, native IPv4 has the best performance, closely followed by native IPv6. The difference is essentially due to the length of the IP header (20 bytes in IPv4 and 40 bytes in IPv6). The tunneling solutions chosen for this research (ISATAP and 6to4) have a similar performance, which is the lowest of the studied technologies, because of the additional IPv4 header in the tunnel.