Description
Use a header of 14 + 4 × vlanTags bytes for zero through two tags.
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.
Use a header of 14 + 4 × vlanTags bytes for zero through two tags.
When to use this tool
Use Ethernet Padding Payload Shortfall when you need a field-level byte count or boundary check.
How to use the tool and how it works
- Enter payloadBytes, vlanTags. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read paddingBytes, frameBytes. Use the output convention below.
Use a header of 14 + 4 × vlanTags bytes for zero through two tags. Add enough padding to reach 60 bytes before FCS, then add four FCS bytes for frameBytes.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| payloadBytes | Payload Bytes | Required. Safe integer; minimum 0; maximum 1500. |
| vlanTags | Vlan Tags | Required. Safe integer; minimum 0; maximum 2. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| paddingBytes | Padding Bytes | Required. Safe integer. |
| frameBytes | Frame Bytes | Required. Safe integer. |
{
"input": {
"payloadBytes": 20,
"vlanTags": 0
},
"output": {
"paddingBytes": 26,
"frameBytes": 64
}
}Limitations and assumptions
- This explicit minimum-size model does not add preamble, gap, or validate actual tag and payload contents.
- 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
- Ethernet Fcs Excluded Frame Length
Add or subtract the four-byte FCS according to includesFcs and return both length conventions.
- Ethernet Preamble Included Length Flag
Subtract eight bytes when reportedBytes includes preamble and SFD, otherwise retain it as frameBytes.