What Is a Default Gateway in Networking?

You can't get to the internet without one

Interior of an airport terminal

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A default gateway lets devices in one network communicate with devices in another network. If your computer, for example, is requesting an internet web page, the request first runs through your default gateway before exiting the local network to reach the internet.

An easier way to understand a default gateway might be to think of it as an intermediate device between the local network and the internet. It's necessary for transferring internal data out to the internet and then back again.

In most homes and small offices, the default gateway is a router that directs traffic from the local network to the cable or DLS modem, which sends it on to the internet service provider (ISP).

The default gateway device passes traffic from the local subnet to devices on other subnets. The default gateway often connects your local network to the internet, although internal gateways for communication within a local network also serve a useful purpose in corporate networks.

The word default in this term just means that it's the default device that's looked for when information needs to be sent through the network.

How Traffic Moves Through a Default Gateway

All the clients on a network point to a default gateway that routes their traffic.

The default gateway in your home network, for example, understands specific routes that must be taken to move your internet requests from your computer out of your network and onto the next piece of equipment that can understand what needs to be done.

From there, the same process happens until your data eventually reaches its intended destination. With each network that the traffic hits, that network's default gateway serves its purpose to relay the information back out to the internet and ultimately back to your device, which initially requested it.

When traffic is bound for other internal devices and not a device external to the local network, the default gateway is still used to understand the request, but instead of sending the data out of the network, it points it to the correct local device.

This process is understood based on the IP address that the originating device requests.

Types of Default Gateways

Internet default gateways are typically one of two types:

  • In home or small business networks with a broadband router to share the internet connection, the home router serves as the default gateway.
  • In home or small business networks without a router, such as for residences with dial-up internet access, a router at the internet service provider location serves as the default gateway.

Default network gateways can also be configured using an ordinary computer instead of a router. These gateways use two network adapters: one is connected to the local subnet and the other is connected to the outside network.

Either routers or gateway computers can be used to network local subnets such as those in larger businesses.

How to Find Your Default Gateway IP Address

You might need to know the IP address of the default gateway if there's a network problem or you need to make changes to your router.

In Microsoft Windows, the IP address of a computer's default gateway can be accessed through Command Prompt with the ipconfig command, as well as through the Control Panel. The netstat and ip route commands are used on macOS and Linux for finding the default gateway address.