ENDEREÇO IP: MASCARA OU CIDR/BIT:  
 
ex: 192.168.0.10 255.255.255.0

  IP Ranges Reserved for Internal Use (Private Networks) :
  Starting IP Address Ending IP Address Subnet Mask
Class A 10.0.0.0 10.255.255.255 255.0.0.0
Class B 172.16.0.0 172.31.255.255 255.255.0.0
Class C 192.168.0.0 192.168.255.255 255.255.255.0

Notice: Undefined index: my_net_info in E:\Inetpub\vhosts\calculadoraip.com.br\httpdocs\internas\calculadora-de-ip1.php on line 153

Notice: Undefined index: my_net_info2 in E:\Inetpub\vhosts\calculadoraip.com.br\httpdocs\internas\calculadora-de-ip1.php on line 154
Use IP & CIDR Netmask: 10.0.0.1/22
Or IP & Netmask:10.0.0.1 255.255.252.0
Or IP & Wildcard Mask:10.0.0.1 0.0.3.255