A类IP地址:0.0.0.0~127.255.255.255;
B类IP地址:128.0.0.0~191.255.255.255;
C类IP地址:192.0.0.0~223.255.255.255;
D类IP地址:224.0.0.0~239.255.255.255
E类IP地址:240.0.0.0~255.255.255.255;