What is a Router?
Routing
Overview
A router selects an outgoing path for an IP destination and decrements TTL or hop limit. It connects distinct broadcast domains rather than forwarding every L2 broadcast. Forwarding needs a suitable route and reachable next hop; successful bidirectional traffic also requires return routing.
Protocol stages
- 1Destination IP
- 2Route lookup
- 3Next hop
- 4Outgoing frame
Interactive exercise
Knowledge check
A host sends to an off-subnet destination with no gateway. What is the primary missing configuration?
Related practice
Lab: default-routeEducational model — not real hardware, traffic or official certification.