✂️

IP Fragmentation & MTU: Why Large Packets Get Split

Simple

Free preview · 2 of 5 steps

MTU: the maximum packet size on each link

Every network link has a Maximum Transmission Unit — the largest frame it can carry. Ethernet is 1500 bytes. PPPoE DSL is 1492. WiFi is typically 1500.

When a packet travels from one link type to another with a smaller MTU, something must happen. IPv4 can fragment the packet into smaller pieces, or refuse and send back an error. This choice — and its implications — affects every large data transfer.

Packets in motion — click to inspect:

1 / 2

Space to play/pause · ← → to step