Segue abaixo o CIDR
/25 = 1bit ----------- mascara sub-rede ----------- 255.255.255.128 ----------- 126 hosts
/26 = 2bits----------- mascara sub-rede ----------- 255.255.255.192 ----------- 62 hosts
/27 = 3bits----------- mascara sub-rede ----------- 255.255.255.224 ----------- 30 hosts
/28 = 4bits----------- mascara sub-rede ----------- 255.255.255.240 ----------- 14 hosts
/29 = 5bits----------- mascara sub-rede ----------- 255.255.255.248 ----------- 6 hosts
/30 = 6bits -- 2^6= 64 sub - redes----------- mascara sub-rede ----------- 255.255.255.252 ----------- 2 hosts
/31 = 7bits----------- mascara sub-rede ----------- 255.255.255.254 ----------- 1 hosts
/32 = 8bits----------- mascara sub-rede ----------- 255.255.255.255 ----------- 0 hosts