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IP Subnet Calculator
IPv4 calculations from CIDR notation
Indirizzo
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Netmask
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Wildcard
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Rete
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Broadcast
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Host min
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Host max
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Host totali
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Classe
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What is CIDR
CIDR (Classless Inter-Domain Routing) is the compact notation for indicating IPv4 subnets. It's written as IP/prefix (e.g. 192.168.1.0/24). The number after the slash indicates how many bits of the netmask are 1: /24 = 24 bits = 255.255.255.0, /16 = 255.255.0.0, /30 = 255.255.255.252.
Calculations shown
- Netmask: the subnet mask (e.g. 255.255.255.0)
- Wildcard: the opposite of the netmask (e.g. 0.0.0.255), used in Cisco ACLs
- Network: the network address (first address in the block)
- Broadcast: the last address in the block
- Host range: the first and last IP assignable to hosts
- Total hosts: 2^(32-CIDR) − 2 (excluding network and broadcast)
Frequently asked questions
Which CIDR for a home network?
For home networks /24 is the standard: 256 total addresses, 254 usable for hosts. It's the default netmask of home routers and DHCP.