FieldengNetworking & Communications
MTU / Fragmentation
Whether a packet fits a path MTU, and by how many bytes it exceeds it.
Networking & Communications
Whether a packet fits a path MTU, and by how many bytes it exceeds it.
App id: NET-14. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
fits if packet ≤ MTU; excess = max(0, packet − MTU)Inputs
| Name | Unit |
|---|---|
| Packet size | B |
| Path MTU | B |
Outputs
| Name | Unit |
|---|---|
| Fits (1 = yes) (hero result) | 1 |
| Excess bytes | B |
| Fragmentation required (1 = yes) | 1 |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
Fits (1 = yes) = 1 | Fits path MTU | info |
Otherwise | Exceeds path MTU | caution |
Assumptions
- Contextual notes only — not an emulation of a network stack.
Provenance
- Size comparison only. Does not implement IPv4 DF or IPv6 PMTUD.