In a high performance computer network system especially that has high-speed networks, an imbalance problem occurs in terms of that network performance is significantly higher than computer capacity. The problem deteriorates performance of the entire system by ineffectively overloading application servers by few high performance clients. In this paper, we present performance analysis and validation of a web server and confirm the possibility of transparent performance enhancement for a high performance computer network system by only changing the configuration of network facilities such as switches and routers. We constructed a local experimental web system and reproduced several cases in which the problem occurred and confirmed that it is possible to solve the problem by only suppressing network traffic on the communication lines for high performance clients. By practically using the network traffic control method it is expectable to provide best performance of application systems in a high-speed network environment in the future.