IP subnet calculator

104.21.58.0-104.21.72.255

104.21.58.0-104.21.59.255
104.21.58.0/23

104.21.60.0-104.21.63.255
104.21.60.0/22

104.21.64.0-104.21.71.255
104.21.64.0/21

104.21.72.0-104.21.72.255
104.21.72.0/24