Calculate CIDR

Enter CIDRs in bulk, or enter an IP address and prefix/subnet mask separately.

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IP address or CIDR Prefix or subnet mask (optional)

Please enter an IP address and CIDR.

Subnet split

Split the network using a new prefix and list 25 entries at a time.

CIDR to split New prefix

Specify the network and the new prefix.

List of split subnets
#	CIDR	First usable IP	Last usable IP	Broadcast	Available count

Check whether the specified IP address is within the CIDR range.

CIDR to check Target IP

You can check whether an IP address is included in a CIDR.

Check the CIDR range and number of available addresses needed for network design, firewall configuration, and cloud VPC and subnet creation.

IPv4 and IPv6 CIDR, and IPv4 subnet mask input
Network range, host count, address type, and IPv4 bit display
Subnet splitting, lists in sets of 25, CSV export, and IP address membership checks

Enter an IP address and CIDR, or a prefix and subnet mask.
Check the network range, host count, and address types in the calculation results.
Split subnets, export CSV, or check IP address membership as needed.

For IPv4, /31 is calculated as a point-to-point connection and /32 as a single host.
IPv6 has no broadcast address.
CSV export of the subnet list is limited to 4,096 entries or fewer.

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