Functions

Function of Network Layer¶

→ Data plane

Like getting through a interchange

Local, per-router function
determine how datagram arriving on router input port is forwarded to output port
take place fast, implemented in hardware

→ Control plane

Like the process of planning trip from source to destination

global, network-wide logic
determine how datagram is routed among routers along end-to-end path from source host to destination host
take place slow(sec), and implemented in software

Forwarding Table