Ethernet Shield doesn't work with router

Hi

I tried to work with the Ethernet Shield Wiznet W5100-M. I jus try the built-in Ethernet/WebServer example. When I connect the shield direct to the PC (with an ethernet cable), it worked. But when I try to connect it to a router, it doesn't work. The IP address is correct, I set it to 192.168.0.202. The router's IP is 192.168.0.1. But I can't ping it from my PC, and the other examples (WebClient, UdpNtpClient) neither working.
Please, help me, what is wrong!

Thanks:
TBC

I guess this isn't an original Arduino Ethernet Shield. We often read about Chinese clone shields that do not work with switches/routers. Some of them are easily fixable by replacing a resistor. I never read about a software problem, all problems I read about were in the hardware.