online CIDR and IP subnet calculator : Check host

31.221.12.228-31.221.12.231
31.221.12.228/30

31.221.12.232-31.221.12.239
31.221.12.232/29

31.221.12.240-31.221.12.255
31.221.12.240/28

31.221.13.0-31.221.13.255
31.221.13.0/24

31.221.14.0-31.221.15.255
31.221.14.0/23

31.221.16.0-31.221.31.255
31.221.16.0/20

31.221.32.0-31.221.63.255
31.221.32.0/19

31.221.64.0-31.221.127.255
31.221.64.0/18

IP subnet calculator 31.221.12.228-31.221.127.255