Definition

router

Contributor(s): Jessica Scarpati

In packet-switched networks such as the internet, a router is a device or, in some cases, software on a computer, that determines the best way for a packet to be forwarded to its destination.

Download this free guide

Download: Overcome Virtual Network Management Challenges

The virtualized network poses challenges to network management systems -- and as more hardware components become virtualized, that challenge becomes even greater. This handbook discusses the steps IT must take to both build and corral their virtualized infrastructure.

Corporate E-mail Address:

You forgot to provide an Email Address.

This email address doesn’t appear to be valid.

This email address is already registered. Please login.

You have exceeded the maximum character limit.

Please provide a Corporate E-mail Address.
- I agree to TechTarget’s Terms of Use, Privacy Policy, and the transfer of my information to the United States for processing to provide me with relevant information as described in our Privacy Policy.
Please check the box if you want to proceed.
- I agree to my information being processed by TechTarget and its Partners to contact me via phone, email, or other means regarding information relevant to my professional interests. I may unsubscribe at any time.
Please check the box if you want to proceed.

A router connects networks. Based on its current understanding of the state of the network it is connected to, a router acts as a dispatcher as it decides which way to send each information packet. A router is located at any gateway (where one network meets another), including each point-of-presence on the internet. A router is often included as part of a network switch.

How does a router work?

A router may create or maintain a table of the available routes and their conditions and use this information along with distance and cost algorithms to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. Routing is a function associated with the network layer (Layer 3) in the standard model of network programming, the Open Systems Interconnection (OSI) model. A Layer 3 switch is a switch that can perform routing functions.

An edge router is a device located at the boundary of a network that connects to other networks, wide area networks or the internet. For home and business computer users who have high-speed internet connections such as cable, satellite or DSL, a router can act as a hardware firewall. Many engineers believe that the use of a router provides better protection against hacking than a software firewall because no computer internet protocol addresses are directly exposed to the internet. This makes port scans (a technique for exploring weaknesses) essentially impossible. In addition, a router does not consume computer resources, which a software firewall does. Commercially manufactured routers are easy to install and are available for hard-wired or wireless networks.

Also see bridge, gateway, hub and switch.

This was last updated in October 2016