CIDR (Classless Inter-Domain Routing) uses a prefix length (e.g., /24) to denote how many leading bits represent the network prefix. The remaining bits represent host addresses. A /24 mask provides 32 - 24 = 8 host bits, yielding 256 total IP addresses (254 usable hosts).
NETWORK & WEB·Client-Side (100% Private)
IPv4 Subnet & CIDR Calculator
Calculate IPv4 network address, broadcast, usable host range, CIDR prefixes (/0 to /32), wildcard masks, and binary octets. Features interactive CIDR slider, VLSM subnet subdivider, and reference cheat sheet.
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FREQUENTLY ASKED QUESTIONS
Frequently Asked Questions about IPv4 Subnet & CIDR Calculator
Quick answers to common questions about usage, conversion rules, privacy guarantees, and best practices.
How does CIDR notation calculate network address ranges?
What is the difference between a Network Address and a Broadcast Address?
The network address is the first address in a subnet range (all host bits 0), identifying the network segment. The broadcast address is the last address in the subnet (all host bits 1), used to send packets to all hosts on the subnet. Neither can be assigned to an individual host.
What is a wildcard mask in networking?
A wildcard mask is the bitwise inverse of a subnet mask (e.g., a 255.255.255.0 mask corresponds to a wildcard mask of 0.0.0.255), commonly used in Cisco Access Control Lists (ACLs) and OSPF routing configurations.
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