IP地址与子网掩码转换表

A类:
子网数目 占用位数子网掩码子网中主机数
 2 1255.128.0.08,388,606
 4 2255.192.0.04,194,302
 8 3255.224.0.02,097,150
 16 4255.240.0.01,048,574
 32 5255.248.0.0524,286
 64 6255.252.0.0262,142
 1287255.254.0.0131,070
 1288255.255.0.065,534 B类:
子网数目 占用位数子网掩码子网中主机数
 2 1255.255.128.0 32,766
 4 2255.255.192.0 16,382
 8 3255.255.224.0 8,190
 16 4255.255.240.0 4,094
 32 5255.255.248.0 2,046
 64 6255.255.252.0 1,022
 1287255.255.254.0 510
 2568255.255.255.0 254
C类:
子网数目 占用位数子网掩码子网中主机数
 2 1255.255.255.128 126
 4 2255.255.255.192 62
 8 3255.255.255.224 30
 16 4255.255.255.240 14
 32 5255.255.255.248 6
 64 6255.255.255.252 2
【IP地址与子网掩码转换表】Table 1.1. CIDR子网表
子网掩码CIDR名称IP数量可用IP数量C类网络的数量255.255.255.255/32111/256255.255.255.254/31201/128255.255.255.252/30421/64255.255.255.248/29861/32255.255.255.240/2816141/16255.255.255.224/2732301/8255.255.255.192/2664621/4255.255.255.128/25128126一半255.255.255.0/242562541255.255.254.0/235125102255.255.252.0/22102410224255.255.248.0/21204820468255.255.240.0/204096409416255.255.224.0/198192819032255.255.192.0/1816,38416,38264255.255.128.0/1732,76832,766128255.255.0.0/1665,53665,534256255.254.0.0/15131,072131,070512255.252.0.0/14262,144262,1421024255.248.0.0/13524,288524,2862048255.240.0.0/121,048,5761,048,5744096255.224.0.0/112,097,1522,097,1508192255.192.0.0/104,194,3044,194,30216,384255.128.0.0/98,388,6088,388,60632,768255.0.0.0/816,777,21616,777,21465,536254.0.0.0/733,554,43233,554,430131,072252.0.0.0/667,108,86467,108,862262,144248.0.0.0/5134,217,728134,217,7261,048,576240.0.0.0/4268,435,456268,435,4542,097,152224.0.0.0/3536,870,912536,870,9104,194,304192.0.0.0/21,073,741,8241,073,741,8228,388,608128.0.0.0/12,147,483,6482,147,483,64616,777,2160.0.0.0/04,294,967,2964,294,967,29433,554,432

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