。（4）第4个子网的IP地址是从“11000000000010011100100011000001”到“11000000000010011100100011111110”，注意此时被网络号所占住的2位主机号为“11”。对应的十进制IP地址范围为19292001931929200254。对应这个子网的子网掩码（或网络地址）为11000000000010011100100011000000，为1929200192。在此列出A、B、C三类网络子网数目与子网掩码的转换表，如下表所示，供参考。表：子网划分与子网掩码对应表
fA类网络划分子网数与对应的子网掩码子网数目248163264128256占用主机号位数12345678子网掩码2551280025519200255224002552400025525800255253002552540025525500子网中可容纳的主机数838860641943022097150104857452428626214213107065534
B类网络划分子网数与对应的子网掩码子网数目248163264128256占用主机号位数12345678子网掩码25525512802552551920255255224025525524002552552480255255252025525525402552552550子网中可容纳的主机数32766163288190409420461022510254
C类网络划分子网数与对应的子网掩码子网数目248163264占用主机号位数123456子网掩码255255255128255255255192255255255224255255255240255255255248255255255252子网中可容纳的主机数12662301462
fr