IP range to CIDR & IP in network check

Convert an IPv4 range to the minimal list of CIDR blocks and check whether an IP address belongs to a network.

Runs in your browser · nothing is sentIP & subnetting

IP range to CIDR

Start IPEnd IP

8 CIDR blocks

192.168.1.10/31 192.168.1.12/30 192.168.1.16/28 192.168.1.32/27 192.168.1.64/26 192.168.1.128/26 192.168.1.192/29 192.168.1.200/32

IP addressNetwork (CIDR)

The address is inside this network.

Two tools in one: turn a start and end IP into CIDR blocks for firewall rules, or test if an address falls inside a network.

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Why do I get several CIDR blocks?

A range that does not align to a power of two cannot be written as a single block, so it is split into the fewest blocks possible.

VPC/subnet plannerPlan subnets inside a VPC or VNet, see usable addresses after provider reservations, catch overlaps, and export Terraform or CloudFormation.
AWS Security Group analyzerPaste a describe-security-groups export to find open ports, redundant and shadowed rules, see a traffic diagram and the impact of removing a rule.
Azure NSG analyzerPaste an Azure NSG export to find open ports, hidden conflicts between subnet and NIC rules, and see a traffic diagram.

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