子网掩码-掩码位-反掩码 对照表

127.255.255.255 = 1 = 128.0.0.0

63.255.255.255 = 2 = 192.0.0.0

31.255.255.255 = 3 = 224.0.0.0

15.255.255.255 = 4 = 240.0.0.0

7.255.255.255 = 5 = 248.0.0.0

3.255.255.255 = 6 = 252.0.0.0

1.255.255.255 = 7 = 254.0.0.0

0.255.255.255 = 8 = 255.0.0.0

0.127.255.255 = 9 = 255.128.0.0

0.63.255.255 = 10 = 255.192.0.0

0.31.255.255 = 11 = 255.224.0.0

0.15.255.255 = 12 = 255.240.0.0

0.7.255.255 = 13 = 255.248.0.0

0.3.255.255 = 14 = 255.252.0.0

0.1.255.255 = 15 = 255.254.0.0

0.0.255.255 = 16 = 255.255.0.0

0.0.127.255 = 17 = 255.255.128.0

0.0.63.255 = 18 = 255.255.192.0

0.0.31.255 = 19 = 255.255.224.0

0.0.15.255 = 20 = 255.255.240.0

0.0.7.255 = 21 = 255.255.248.0

0.0.3.255 = 22 = 255.255.252.0

0.0.1.255 = 23 = 255.255.254.0

0.0.0.255 = 24 = 255.255.255.0

0.0.0.127 = 25 = 255.255.255.128

0.0.0.63 = 26 = 255.255.255.192

0.0.0.31 = 27 = 255.255.255.224

0.0.0.15 = 28 = 255.255.255.240

0.0.0.7 = 29 = 255.255.255.248

0.0.0.3 = 30 = 255.255.255.252

0.0.0.1 = 31 = 255.255.255.254

0.0.0.0 = 32 = 255.255.255.255