Network tools
Netmask calculator
The tool breaks the specified IPv4 address range into a minimum set of CIDR blocks. This is useful for planning subnets, firewall rules, and scope aggregation.
Rozbij zakres na bloki CIDR
Enter the `Subnet Range`, e.g. `192.168.5.5-192.168.5.9`.
What is the Netmask Calculator used for?
The tool allows you to break down any contiguous IPv4 range into the smallest possible number of CIDR blocks that exactly cover the specified range.
Most common applications
You can prepare router rules, ACLs, firewall entries, routing ranges, or check how best to save a specific address range in the form of network blocks.
How the score works
Each line shows one CIDR block. Together, all lines cover the entered range exactly without going beyond its limits.