IPv6 Hextet Field Extractor
Extract one zero-based IPv6 hextet in network order after existing address parsing; returns its exact 16-bit numeric value.
Description
Extract one zero-based IPv6 hextet in network order after existing address parsing; returns its exact 16-bit numeric value.
An IPv6 address contains eight 16-bit hextets in network order. This tool selects one by its zero-based left-to-right position.
When to use this tool
Extract one zero-based IPv6 hextet in network order after existing address parsing; returns its exact 16-bit numeric value.
- Prepare the supplied address, index 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, index. 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.value. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Validate index from 0 to 7. Parse the address, shift right by 16 times (7 minus index), mask to 65,535 and return the numeric value.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 |
| index | index. | Integer from 0 to 7 inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.value | The value value under the stated formula or text convention. |
{
"input": {
"address": "::abcd",
"index": 7
},
"output": {
"result": {
"value": 43981
}
}
}Limitations and assumptions
- The result is a number rather than hexadecimal text. No semantic field meaning or address assignment is checked.
- 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 Low Bit Field Extractor
Extract an explicitly sized low-bit IPv6 field as decimal integer text, including zero-width zero; no interface-identifier semantics inferred.
- IPv6 Explicit Field Replacer
Replace an exact IPv6 bit field with least-significant-bit offset zero, preserving all unmasked address bits; no assignment or routing semantics.