电脑技术学习

IP地址与子网掩码转换表

dn001
A类:
子网数目 占用位数    子网掩码    子网中主机数
 2     1    255.128.0.0    8,388,606
 4     2    255.192.0.0    4,194,302
 8     3    255.224.0.0    2,097,150
 16     4    255.240.0.0    1,048,574
 32     5    255.248.0.0    524,286
 64     6    255.252.0.0    262,142
 128    7    255.254.0.0    131,070
 128    8    255.255.0.0    65,534

B类:
子网数目 占用位数    子网掩码    子网中主机数
 2     1    255.255.128.0   32,766
 4     2    255.255.192.0   16,382
 8     3    255.255.224.0   8,190
 16     4    255.255.240.0   4,094
 32     5    255.255.248.0   2,046
 64     6    255.255.252.0   1,022
 128    7    255.255.254.0   510
 256    8    255.255.255.0   254

C类:
子网数目 占用位数    子网掩码    子网中主机数
 2     1    255.255.255.128   126
 4     2    255.255.255.192   62
 8     3    255.255.255.224   30
 16     4    255.255.255.240   14
 32     5    255.255.255.248   6
 64     6    255.255.255.252   2

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 /32 1 1 1/256
255.255.255.254 /31 2 0 1/128
255.255.255.252 /30 4 2 1/64
255.255.255.248 /29 8 6 1/32
255.255.255.240 /28 16 14 1/16
255.255.255.224 /27 32 30 1/8
255.255.255.192 /26 64 62 1/4
255.255.255.128 /25 128 126 一半
255.255.255.0 /24 256 254 1
255.255.254.0 /23 512 510 2
255.255.252.0 /22 1024 1022 4
255.255.248.0 /21 2048 2046 8
255.255.240.0 /20 4096 4094 16
255.255.224.0 /19 8192 8190 32
255.255.192.0 /18 16,384 16,382 64
255.255.128.0 /17 32,768 32,766 128
255.255.0.0 /16 65,536 65,534 256
255.254.0.0 /15 131,072 131,070 512
255.252.0.0 /14 262,144 262,142 1024
255.248.0.0 /13 524,288 524,286 2048
255.240.0.0 /12 1,048,576 1,048,574 4096
255.224.0.0 /11 2,097,152 2,097,150 8192
255.192.0.0 /10 4,194,304 4,194,302 16,384
255.128.0.0 /9 8,388,608 8,388,606 32,768
255.0.0.0 /8 16,777,216 16,777,214 65,536
254.0.0.0 /7 33,554,432 33,554,430 131,072
252.0.0.0 /6 67,108,864 67,108,862 262,144
248.0.0.0 /5 134,217,728 134,217,726 1,048,576
240.0.0.0 /4 268,435,456 268,435,454 2,097,152
224.0.0.0 /3 536,870,912 536,870,910 4,194,304
192.0.0.0 /2 1,073,741,824 1,073,741,822 8,388,608
128.0.0.0 /1 2,147,483,648 2,147,483,646 16,777,216
0.0.0.0 /0 4,294,967,296 4,294,967,294 33,554,432