IPv4 CIDR Relation Classifier
Classify normalized IPv4 CIDR set relation as equal, contains, contained-by or disjoint; host bits in supplied addresses are masked.
Description
Classify normalized IPv4 CIDR set relation as equal, contains, contained-by or disjoint; host bits in supplied addresses are masked.
Two normalized IPv4 CIDR blocks can be equal, nested or disjoint. Comparing inclusive boundaries makes containment direction explicit.
When to use this tool
Classify normalized IPv4 CIDR set relation as equal, contains, contained-by or disjoint; host bits in supplied addresses are masked.
- Prepare the supplied left, leftPrefix, right, rightPrefix fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter left, leftPrefix, right, rightPrefix. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.relation. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Normalize left and right at their prefix lengths. Return equal, contains, contained-by, disjoint or overlap according to their endpoint relationships.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| left | Address text for the family named by this tool. Prefix lengths are separate fields where shown. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| leftPrefix | left prefix. | Safe integer |
| right | Address text for the family named by this tool. Prefix lengths are separate fields where shown. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| rightPrefix | right prefix. | Safe integer |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.relation | The relation value under the stated formula or text convention. |
{
"input": {
"left": "10.0.0.0",
"leftPrefix": 24,
"right": "10.0.0.128",
"rightPrefix": 25
},
"output": {
"result": {
"relation": "contains"
}
}
}Limitations and assumptions
- Aligned CIDR blocks do not ordinarily partially overlap. The generic overlap branch is not a route-conflict or policy verdict.
- IPv4 input uses strict dotted-decimal octets without leading zeros or surrounding whitespace. IPv6 accepts its supported compressed or full spellings and trims surrounding whitespace, but rejects zone identifiers; embedded dotted IPv4 uses the strict IPv4 spelling. IPv6 address outputs are fully expanded unless stated otherwise.
- All declared input fields are required and unexpected top-level fields are rejected. Numbers must be finite; lists are limited to 128 entries and ordinary text fields to 8,192 UTF-16 code units, with tighter limits where stated.
- JSON text inputs must parse within bounded nesting and size limits. Numeric outputs outside the safe finite range are rejected; large exact integer results use decimal strings. Indexes and half-open spans are zero-based unless a rank is explicitly described as one-based.
Alternative or Complementary methods
Use address-set arithmetic for prefix planning and a routing or interface inspection for deployed configuration. Membership and overlap do not establish reachability, ownership or route preference.
References
Similar or alternative tools
- ipv4 cidr
Compute network address, broadcast, host range, and capacity for an IPv4 CIDR block.
- integer to ipv4
Convert an unsigned 32-bit integer into dotted-decimal IPv4 form.