What Is a Router?
a Router — a Layer 3 device that forwards packets between different networks using IP addresses — the device that connects your network to other networks and the internet.
How it works
A router examines each packet's destination IP, consults its routing table, and forwards the packet toward the best next hop. It separates broadcast domains, so each connected network stays independent. Routers also commonly provide NAT, DHCP, firewalling and WAN connectivity.
Why it matters
The router is the boundary between networks — no router, no internet. Understanding routing (how it chooses paths via administrative distance, metrics and longest-prefix match) is the heart of CCNA. Compare it with a switch and hub, or a Layer 3 switch.
Frequently asked questions
What does a router do?
It forwards packets between different networks using IP addresses, chooses the best path from its routing table, and connects local networks to the internet.
What is the difference between a router and a switch?
A router forwards between networks by IP address (Layer 3) and separates broadcast domains; a switch forwards within a network by MAC address (Layer 2).
Does a router provide Wi-Fi?
A wireless router does; a plain router provides only wired routing. Home gateways typically combine router, Wi-Fi and modem functions.
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