In this paper, the authors bash shell scripts using the host Linux command were applied for testing the performance and stability of different DNS64 server implementations. Because of their inefficiency, a small multi-threaded C/C++ program (named DNS64PERF) was written which can directly send DNS AAAA record queries. After the introduction to the essential theoretical background about the structure of DNS messages and TCP/IP socket interface programming, the design decisions and implementation details of their DNS64 performance test program are disclosed.