IP subnet calculator

91.72.172.0-91.72.186.255

91.72.172.0-91.72.175.255
91.72.172.0/22

91.72.176.0-91.72.183.255
91.72.176.0/21

91.72.184.0-91.72.185.255
91.72.184.0/23

91.72.186.0-91.72.186.255
91.72.186.0/24