Calculate the minimal set of CIDR subnet blocks covering any IP address range (IPv4). Ideal for cloud security groups, AWS VPC, UFW, and routing tables.
| CIDR Block | Subnet Mask | Total Hosts | Wildcard Mask | Action |
|---|---|---|---|---|
| Enter valid start and end IP addresses and click Calculate. | ||||
Network routers, firewalls (iptables, UFW, pfSense), and cloud security policies (AWS VPC, GCP Cloud Armor, Cloudflare WAF) require CIDR subnet notation.
Enter your start and end IP addresses to compute the minimal collection of non-overlapping CIDR blocks with exact host counts and netmasks.
It calculates the binary boundaries of the start and end IP addresses and merges contiguous ranges into the largest possible valid power-of-two CIDR subnets without overlapping or including extra IPs.
Yes. Cloud firewalls require CIDR notation (e.g., 192.168.1.0/24) rather than arbitrary IP ranges. This tool converts ranges directly into valid cloud firewall rules.
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