CALCULATE / IP40BPS / MODULE
IPV4 SUBNET
Calculate IPv4 network boundaries, masks and host capacity from an address and CIDR prefix. All arithmetic stays in this browser.
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COMMON PREFIXES
Traditional IPv4 subnets reserve network and broadcast addresses. /31 is interpreted as a point-to-point pair and /32 as one host address. Private/public scope is descriptive only and does not test reachability.
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RESULT / EXPLAINED
Exact address math, with operational claims kept separate.
The network-planning tools perform deterministic IPv4/IPv6 arithmetic locally. They describe address-space relationships, not whether a network is deployed correctly.
What is exact
Network boundaries, containment, ranges, prefix lengths, masks and exact aggregation/splitting results come from deterministic address arithmetic.
Canonical output
Normalized network values remove host bits where appropriate. Containment means one calculated address range fully includes another; overlap means ranges intersect.
No live network validation
The browser does not confirm routing tables, VLANs, DHCP, firewall rules, ownership, reachability or whether the calculated prefix is appropriate for your deployment.
Before deployment
Use the arithmetic result as a planning input, then verify it against the real network design, routing/firewall policy and authoritative address allocation.
0BPS SHOWS MEASURED OR CALCULATED FACTS SEPARATELY FROM INTERPRETATION. WHERE A RESULT IS ADVISORY, ESTIMATED OR DESTINATION-SPECIFIC, THE LIMIT IS STATED IN THE TOOL.
REFERENCE / FAQ
COMMON QUESTIONS
What does an IPv4 CIDR prefix mean?
The prefix length tells you how many of the 32 IPv4 bits identify the network. For example, /24 leaves eight host bits and covers 256 total addresses.
Why does /31 show two usable addresses?
RFC 3021 allows /31 networks on point-to-point links, where the two addresses can be used by the two endpoints instead of reserving network and broadcast host slots.
Does the calculator send my IP address anywhere?
No. IPv4 subnet arithmetic is performed locally in your browser.
The calculator performs deterministic 32-bit IPv4 subnet arithmetic locally in the browser. No address is sent to the server.
/31 networks are treated as point-to-point address pairs and /32 represents one host address.
PRACTICAL / EXAMPLES
PUT THE NUMBER IN CONTEXT.
Short examples using the same units and assumptions as this module.
Network 192.168.1.0, broadcast 192.168.1.255 and 254 traditional usable host addresses.
A /30 covers four addresses: network, two host addresses and broadcast.