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What Is a WAN Port?

A router with a cord plugged into the WAN port.
The back of a router, showing the power, WAN, and LAN ports.
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  • Written By: M. McGee
  • Edited By: Lauren Fritsky
  • Last Modified Date: 11 August 2014
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Most networks consist of two major zones—the local area network (LAN) and the wide area network (WAN). A LAN is the internal network, whether it is a house with two computers or a high-rise office building with thousands doesn’t matter. The WAN is the network outside the LAN; this is both other internal networks and the full Internet. A WAN port is the portal by which information passes back and forth between the LAN and the WAN.

Most users will find a WAN port on a network router. A common home router has one WAN port and four LAN ports. Some routers refer to them as an uplink (for the WAN port) and wired connections (for LAN ports). This port take in information from a high-speed Internet source, such as a cable modem, and splits it to multiple machines inside the home network. While the majority of home routers have four LAN ports, there can be as few as zero or an unlimited amount, although rarely more than eight.

These five ports all appear as rectangular holes on the back of the device. Each of them is designed to have a network cable plugged into it. The WAN port generally sits apart from the other ports to make it easier to identify, but it otherwise looks the same as the LAN ports.

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The important difference in the two port types is inside the router. The WAN port takes in information from the outside network or the Internet. The information is filtered through the router’s internal firewall and routing system. Then the information is sent to the proper LAN port or out over a wireless connection to a wireless source.

In addition to the routing and firewall abilities, routers also include switching functions. This allows computers that are connected through the LAN ports only to communicate with each other. This switching function bypasses the router’s standard firewall, and the computers are all on the same network. Users can use this function to connect multiple routers to one another to increase the size of their network.

If they were to connect multiple routers together using the WAN port, they could have multiple internal networks that operate independently of one another. For instance, the high-speed information comes to a single router, and that router then has connections from its LAN ports to three other routers where it plugs into their WAN ports. These internal networks would contain independent information and have no more of a connection to one another than they have to a network in a different building.

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Discuss this Article

anon962208
Post 10

Not all modems are connected to a phone line / Ethernet modem anymore (in which case, the port is similar to LAN ports) - cable routers (which play both modem and router parts in a network) have a different looking WAN port.

anon341974
Post 5

Excellent post. I am able to understand the difference very clearly. Thank you.

anon173273
Post 4

So from the LAN ports in main router, connect to WAN ports of other routers to spread out wifi access?

g00dquestion
Post 3

@dtortorelli- Typically a 2 wan port router is more than sufficient for a home network. Configuration depends largely on what kind of hardware you have. Are you looking for a wireless or wired setup? The configuration is going to vary based on what you need. These days most routers come with software that can walk a home user through step-by-step once you know what kind of connection you want.

dtortorelli
Post 2

I have found the hardest part of setting up my home network has been figuring out how to configure my router. Can anyone give me some hints and tips on how to get this up and running without a lot of fuss?

sammyG
Post 1

Since I don't work with computer technology often, I really don't see WAN ports often but when I do, I know what they are for. The most that I ever deal with them is when I am connecting a router to a broad band modem connection. This usually involves me using cat. 5 ethernet wiring as well as a couple of end connection pieces, that are called RJ-45 jacks.

I can always tell the difference between these jacks and an RJ-11 jack, which is used for telephone applications, because the RJ-45 jack is essentially twice as wide. These jacks that are made for WAN ports carry 8 individual wires as opposed to the four that are carried via a telephone line cable.

These extra pairs of twisted copper mean that much data can be sent at the fast rates that people expect these days. I'm glad engineers made WAN ports so we could move beyond the world of dial-up internet access.

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