IPv6 Hextet Zero Run Profile
Profile exact zero-hextet runs of a parsed IPv6 address and retain every longest tie; does not itself choose a compression spelling.
Description
Profile exact zero-hextet runs of a parsed IPv6 address and retain every longest tie; does not itself choose a compression spelling.
Zero-hextet runs help explain possible IPv6 compression spellings. Preserving all longest ties keeps measurement separate from formatting policy.
When to use this tool
Profile exact zero-hextet runs of a parsed IPv6 address and retain every longest tie; does not itself choose a compression spelling.
- Prepare the supplied address 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 address. 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.runs, result.longestIndexes. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Parse eight hextets and scan for contiguous zero groups. Return runs as zero-based half-open start/end spans and longestIndexes as indexes into that run list for every maximum-length tie.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| address | 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 |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.runs | The runs list in the ordering and representation described above. |
| result.longestIndexes | The longest indexes list in the ordering and representation described above. |
{
"input": {
"address": "::1"
},
"output": {
"result": {
"runs": [
{
"start": 0,
"end": 7
}
],
"longestIndexes": [
0
]
}
}
}Limitations and assumptions
- This does not select or emit a compressed address. With no zero hextets, both lists are empty.
- 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
- IPv6 Hextet Field Extractor
Extract one zero-based IPv6 hextet in network order after existing address parsing; returns its exact 16-bit numeric value.
- Integer String IPv6 Address
Format an exact unsigned 128-bit decimal integer as fully expanded lowercase IPv6 using the existing group formatter.