案例分析。。。。。WIN2003

在Internet上的一个C类网络196.168.1.0，要为5个单位所共用，每个单位需要一个独立的子网。现状是A单位的机器数目最多，可能会扩展到29台。请问子网该如何划分？划分的子网个数是多少？并写出每个子网子网号。每个子网的最大主机数目是多少？(请写出详细的计算过程)

196.168.1.0

掩码位：27

255.255.255.224

每个子网的有效主机为30台

可以使用的子网如下

子网 , 有效的主机 , 广播地址
196.168.1.0 , 196.168.1.1 到 196.168.1.30 , 196.168.1.31
196.168.1.32 , 196.168.1.33 到 196.168.1.62 , 196.168.1.63
196.168.1.64 , 196.168.1.65 到 196.168.1.94 , 196.168.1.95
196.168.1.96 , 196.168.1.97 到 196.168.1.126 , 196.168.1.127
196.168.1.128 , 196.168.1.129 到 196.168.1.158 , 196.168.1.159
196.168.1.160 , 196.168.1.161 到 196.168.1.190 , 196.168.1.191
196.168.1.192 , 196.168.1.193 到 196.168.1.222 , 196.168.1.223
196.168.1.224 , 196.168.1.225 到 196.168.1.254 , 196.168.1.255
196.168.2.0 , 196.168.2.1 到 196.168.2.30 , 196.168.2.31
196.168.2.32 , 196.168.2.33 到 196.168.2.62 , 196.168.2.63
196.168.2.64 , 196.168.2.65 到 196.168.2.94 , 196.168.2.95
196.168.2.96 , 196.168.2.97 到 196.168.2.126 , 196.168.2.127
196.168.2.128 , 196.168.2.129 到 196.168.2.158 , 196.168.2.159
196.168.2.160 , 196.168.2.161 到 196.168.2.190 , 196.168.2.191
196.168.2.192 , 196.168.2.193 到 196.168.2.222 , 196.168.2.223
196.168.2.224 , 196.168.2.225 到 196.168.2.254 , 196.168.2.255
196.168.3.0 , 196.168.3.1 到 196.168.3.30 , 196.168.3.31
196.168.3.32 , 196.168.3.33 到 196.168.3.62 , 196.168.3.63
196.168.3.64 , 196.168.3.65 到 196.168.3.94 , 196.168.3.95
196.168.3.96 , 196.168.3.97 到 196.168.3.126 , 196.168.3.127

对吧？