Work out fragmentation overhead instantly with clear inputs, formula shown and shareable results.
IPv4 fragmentation splits the payload into chunks whose size must be a multiple of eight bytes, and each fragment carries its own 20-byte header. The byte overhead is modest but the packet-rate increase is not: doubling packets per second doubles the interrupt and forwarding-table work, and losing any single fragment destroys the entire original datagram.
Fragmentation
payload per fragment = floor((MTU - 20) / 8) x 8; fragments = ceil(payload / payload per fragment); overhead = fragments x 20 - 20
The receiver cannot reassemble the datagram, so every fragment already received is discarded. Effective loss is multiplied by the fragment count.
Not in routers. Only the source may fragment, using an extension header, and routers drop oversized packets with a Packet Too Big message instead.