00000000.00000000.00000000.00000000

111111111.111111111.111111111.111111111 
    8    .    8    .   8     .   8    =/32 (4 octetos é igual 32 bits)
111111111.111111111.111111111.00000000= /24 = 0                (Mask 255.255.255.0)
111111111.111111111.111111111.10000000= /25 = 128              (Mask 255.255.255.128)
111111111.111111111.111111111.11000000= /26 = 128+64 = 192     (Mask 255.255.255.192)
111111111.111111111.111111111.11100000= /27 = 128+64+32 = 224  (Mask 255.255.255.224)
111111111.111111111.111111111.11110000= /28 = 128+64+32+16 = 240  (Mask 255.255.255.240)
111111111.111111111.111111111.11111000= /29 = 128+64+32+16+8 = 248  (Mask 255.255.255.248)
111111111.111111111.111111111.11111100= /30 = 128+64+32+16+8+4 = 252  (Mask 255.255.255.252)


 1°    2°    3°   4°  5°   6°   7°   8°
 1     1     1    1   1    1    1    1  
128   64    32    16  8    4    2    1