Reference

IPv4 Subnet Calculator

A compact CIDR calculator for network debugging, firewall rules and cloud VPC planning. Enter an IPv4 address with prefix and get the full subnet report instantly.

subnet report
Address
192.168.10.42
CIDR
/24
Netmask
255.255.255.0
Wildcard
0.0.0.255
Network
192.168.10.0
Broadcast
192.168.10.255
First usable
192.168.10.1
Last usable
192.168.10.254
Usable hosts
254
Total addresses
256
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01

How to use

  1. 01Enter an IPv4 CIDR such as 192.168.10.42/24.
  2. 02Review network, broadcast, netmask and host range.
  3. 03Copy the full subnet report when documenting rules.
02

FAQ

Does it support IPv6?
Not in this tool. It focuses on fast IPv4 CIDR math. IPv6 planning deserves a separate interface.
How are /31 and /32 handled?
They are treated as point-to-point or single-address ranges with zero traditional usable hosts.
03

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