How a Router Works — Packet Forwarding

Initializing routing engine…

ROUTER

L3 Forwarding Engine

eth0

192.0.2.0/24

eth1

198.51.100.0/24

eth2

203.0.113.0/24

eth3

unused

Routing Table

DestinationGatewayInterface

192.0.2.0/24—eth0

198.51.100.0/24—eth1

203.0.113.0/24198.51.100.1eth1

0.0.0.0/0192.0.2.1eth0

Incoming Packet

SRC IP—

DST IP—

TTL—

Ingress—

Step 1 / 5

A packet arrives at the router's interface.