Fragment for a smaller link
04IPv4 can split a datagram when a next link cannot carry its full size, unless fragmentation is prohibited.
Terms in this drawing
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 3.1 ↗
RFC 791 · § 3.1EXAMPLE
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03
With DF set, reject the oversized datagram instead.
With DF set, reject the oversized datagram instead.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
RFC 791 · IPv4RFC 8200 § 4.5 · IPv6
IPv6 routers do not fragment packets; only the source performs IPv6 fragmentation. These are different IP versions.
Read the updated RFC section ↗DF forbids fragmentation; MF identifies a fragment with more fragments after it.
- DF forbids fragmentation; MF identifies a fragment with more fragments after it.
- Fragment Offset uses eight-octet units, and Identification helps associate the pieces.
The drawing is a simplified worked example. Follow the linked RFC and its updates for implementation requirements.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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