A.3. IPV4网络掩码对照表

表 A.3. IPV4网络掩码对照表

序号

子网掩码

CIDR

总IP数

可用IP数

C网子网数

1

255.255.255.255

/32

1

1

1/256

2

255.255.255.254

/31

2

0

1/128

3

255.255.255.252

/30

4

2

1/64

4

255.255.255.248

/29

8

6

1/32

5

255.255.255.240

/28

16

14

1/16

6

255.255.255.224

/27

32

30

1/8

7

255.255.255.192

/26

64

62

1/4

8

255.255.255.128

/25

128

126

1/2

9

255.255.255.0

/24

256

254

1

10

255.255.254.0

/23

512

510

2

11

255.255.252.0

/22

1024

1022

4

12

255.255.248.0

/21

2048

2046

8

13

255.255.240.0

/20

4096

4094

16

14

255.255.224.0

/19

8192

8190

32

15

255.255.192.0

/18

16,384

16,382

64

16

255.255.128.0

/17

32,768

32,766

128

17

255.255.0.0

/16

65,536

65,534

256

18

255.254.0.0

/15

131,072

131,070

512

19

255.252.0.0

/14

262,144

262,142

1024

20

255.248.0.0

/13

524,288

524,286

2048

21

255.240.0.0

/12

1,048,576

1,048,574

4096

22

255.224.0.0

/11

2,097,152

2,097,150

8192

23

255.192.0.0

/10

4,194,304

4,194,302

16,384

24

255.128.0.0

/9

8,388,608

8,388,606

32,768

25

255.0.0.0

/8

16,777,216

16,777,214

65,536

26

254.0.0.0

/7

33,554,432

33,554,430

131,072

27

252.0.0.0

/6

67,108,864

67,108,862

262,144

28

248.0.0.0

/5

134,217,728

134,217,726

1,048,576

29

240.0.0.0

/4

268,435,456

268,435,454

2,097,152

30

224.0.0.0

/3

536,870,912

536,870,910

4,194,304

31

192.0.0.0

/2

1,073,741,824

1,073,741,822

8,388,608

32

128.0.0.0

/1

2,147,483,648

2,147,483,646

16,777,216

33

0.0.0.0

/0

4,294,967,296

4,294,967,294

33,554,432