IP Address Calculator
Calculate network addresses, subnet mask and host range from CIDR notation.
10.0.0.0/8, 172.16.0.0/12, 192.168.1.0/24). Prefisso rapido
Risultati
| Parametro | Valore | |
|---|---|---|
| Indirizzo di rete | 192.168.1.0 | |
| Indirizzo broadcast | 192.168.1.255 | |
| Subnet mask | 255.255.255.0 | |
| Wildcard mask | 0.0.0.255 | |
| Primo host utilizzabile | 192.168.1.1 | |
| Ultimo host utilizzabile | 192.168.1.254 | |
| Host totali | 256 | |
| Host utilizzabili | 254 | |
| Classe IP | C | |
| Notazione CIDR (network) | 192.168.1.0/24 |
Rappresentazione binaria
11000000.10101000.00000001.0000000011111111.11111111.11111111.00000000Come utilizzare CIDR Calculator
Enter IP address and prefix
Write an IPv4 address followed by the network prefix in CIDR format (e.g. 192.168.1.0/24). The prefix indicates how many bits from left to right identify the network.
Choose a quick prefix or enter it manually
Use fixed-width chips (/8, /16, /24, /28, /30, /32) to apply common subnets, or enter the desired prefix directly in the input field.
Analyze results of subnet
Tool calculates network address, broadcast, subnet mask, wildcard mask, first and last usable hosts, total hosts, and IP class with binary representation of IP and masks.
Copy values with a single click
Each row of the result table has a quick copy button, useful for pasting values directly into router, firewall or network configuration files.
Suggerimenti
- Use /30 or /31 for point-to-point connections between two routers to conserve public and private IP addresses.
- If the address you enter does not match the exact start of the subnet, the tool will still calculate the correct network address by rounding to the prefix bits.
- Observe the binary representation to visually understand which bits are fixed (network) and which variable (host): this is the fastest way to learn subnetting.
Domande frequenti
What does CIDR notation mean?
CIDR (Classless Inter-Domain Routing) expresses a network as an IP address followed by a slash and a number (e.g., /24), which indicates how many bits of the address are reserved for the network. The remaining bits identify available hosts in that subnet.
How many hosts are available in a subnet?
Total hosts are 2 raised to (32 - prefix). Actually usable hosts are that value minus 2, as the first address is reserved for the network and the last for broadcast (except for /31 and /32 which follow different rules).
Why are there no usable hosts with /31 and /32?
Prefix /32 identifies a single host (no network or broadcast subtraction). Prefix /31, according to RFC 3021, is designed for point-to-point connections and uses both available host addresses without a dedicated broadcast address.
What is the purpose of the calculated wild card mask from the tool?
The wildcard mask is the binary complement of the subnet mask and is used mainly in Cisco router ACLs and some OSPF configurations where instead of the subnet mask, the range of addresses corresponding to a match is specified.
How do I understand an IPv4 address class?
Class history depends on the first octet: Class A (0-127), Class B (128-191), Class C (192-223), Class D multicast (224-239), Reserved Class E (240-255). The tool shows it automatically, even though CIDR has replaced classful addressing in modern routing.