Packets vs Frames
Network Fundamentals
Overview
An IP packet identifies source/destination across routed networks. An Ethernet frame delivers that packet over one local link. Routers remove incoming link headers, update forwarding-relevant IP fields and create a new outgoing frame. Switches usually forward frames within a VLAN without routing the packet.
Protocol stages
- 1Ingress Ethernet frame
- 2Router removes L2
- 3IP route decision
- 4New L2 frame
Interactive exercise
Knowledge check
After a packet crosses a router, which addresses normally change at each Ethernet hop?
Educational model — not real hardware, traffic or official certification.