Description
Count two hardware and two protocol addresses as 2 × (hardwareLength + protocolLength), then add the fixed eight-byte ARP header.
A wire-format length may count headers, payload, padding, or only part of an enclosing message. Offsets and exclusive ends must use a clearly stated byte convention.
Count two hardware and two protocol addresses as 2 × (hardwareLength + protocolLength), then add the fixed eight-byte ARP header.
When to use this tool
Use Arp Hardware Protocol Address Span when you need a field-level byte count or boundary check.
How to use the tool and how it works
- Enter hardwareLength, protocolLength. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read addressBytes, packetBytes. Use the output convention below.
Count two hardware and two protocol addresses as 2 × (hardwareLength + protocolLength), then add the fixed eight-byte ARP header.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| hardwareLength | Hardware Length | Required. Safe integer; minimum 0; maximum 255. |
| protocolLength | Protocol Length | Required. Safe integer; minimum 0; maximum 255. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| addressBytes | Address Bytes | Required. Safe integer. |
| packetBytes | Packet Bytes | Required. Safe integer. |
{
"input": {
"hardwareLength": 6,
"protocolLength": 4
},
"output": {
"addressBytes": 20,
"packetBytes": 28
}
}Limitations and assumptions
- This computes a layout size from supplied lengths; hardware and protocol combinations are not validated.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Compare the computed span with the actual captured buffer and validate its contents separately.
References
Similar or alternative tools
- DNS Resource Record Rdata Span
Add start and length to obtain endExclusive.
- Network: Arp Opcode Single Field Label
Label opcodes 1-4 as ARP-request, ARP-reply, RARP-request, and RARP-reply.