18
Prefixos
      Máscara            Prefixo
0.0.0.0 X/0
128.0.0.0 X/1
192.0.0.0 X/2
224.0.0.0 X/3
240.0.0.0 X/4
248.0.0.0 X/5
252.0.0.0 X/6
254.0.0.0 X/7
255.0.0.0 X/8
255.128.0.0 X/9
255.192.0.0 X/10
255.224.0.0 X/11
255.240.0.0 X/12
255.248.0.0 X/13
255.252.0.0 X/14
255.254.0.0 X/15
      Máscara            Prefixo
255.255.0.0 X/16
255.255.128.0 X/17
255.255.192.0 X/18
255.255.224.0 X/19
255.255.240.0 X/20
255.255.248.0 X/21
255.255.252.0 X/22
255.255.254.0 X/23
255.255.255.0 X/24
255.255.255.128 X/25
255.255.255.192 X/26
255.255.255.224 X/27
255.255.255.240 X/28
255.255.255.248 X/29
255.255.255.252 X/30
255.255.255.254 X/31
255.255.255.255 X/32
rfc3021