/32 == .255 == 1 IP
 /28 == .240 == 16 IPs
 /27 == .224 == 32 IPs 
 /26 == .192 == 64 IPs
 /25 == .128 == 128 IPs
 /24 == .0 == class C == 255 IPs
 /16 == class b
 /8  == class A