Group IP Addresses

Collapse a list of addresses into the smallest set of CIDR blocks that covers exactly the same addresses and no others. Takes bare addresses, 10.0.0.0/24 , 10.0.0.1-10.0.0.9 and 10.0.0.0 255.255.255.0 , one per line or comma-separated, and ignores # comments. The floor option widens blocks to a chosen prefix when a shorter rule set matters more than an exact one.