What Is a Router and How Does it Work?

Everything to know about setting up your residential gateway

Linksys EA8500 Router
Linksys EA8500 Router.

Belkin International, Inc.

The router, at least the common home network device that we usually call a router, is the piece of network hardware that allows communication between your local home network — i.e. your personal computers and other connected devices — and the Internet.

The router used in home and small networks is more accurately called a residential gateway but you'll never see them called that.

What is a Router For?

A router is the first line of security from intrusion into a network. Enabling the highest level of security on the router is the best way to keep your computer system and information safe from attack.

Routers contain software called firmware that should be updated as released by the router manufacturer.

Most routers connect to other network devices only via network cables and do not require drivers to operate in Windows or other operating systems. However, routers that connect to a computer via a USB or FireWire typically require drivers to operate properly.

Routers often act as the DHCP servers in small networks, issuing unique IP addresses.

Most routers are manufactured by companies like Linksys, 3Com, Belkin, D-Link, Motorola, TRENDnet, and Cisco, but there are many others.

Routers come in many shapes and sizes, as you can see below:

Photo of an ASUS router
Photo of a Netgear router
Photo of an eero router
Photo of a Netgear router
Photo of a TP-LINK router
Photo of a TP-LINK router

How Routers Work

Routers connect a modem — like a fiber, cable, or DSL modem — to other devices to allow communication between those devices and the Internet. Most routers, even wireless routers, usually feature several network ports to connect numerous devices to the Internet simultaneously.

Typically, a router connects physically, via a network cable, to the modem via the 'Internet' or 'WAN' port and then physically, again via a network cable, to the network interface card in whatever wired network devices you may have. A wireless router can connect via various wireless standards to devices that also support the particular standard used.

The IP address assigned to the 'WAN' or 'Internet' connection is a public IP address. The IP address assigned to the 'LAN' or local network connection is a private IP address. The private IP addresses assigned to a router is usually the default gateway for the various devices on the network.

Wireless routers, and wired routers with multiple connections, also act as simple network switches allowing the devices to communicate with each other. For example, several computers connected to a router can be configured to share printers and files amongst themselves.

Common Things You Might Do

Here are some common things you might do that involve a router: