WAN-Ports: What Are They Used For On Your Router?

What is a WAN-Port and what does it do? You can't use the extra ethernet port on the back of the router for your fifth computer. In router manuals and guide books on the internet, WAN and LAN ports are often listed, and the ports can be found on almost any router.is no doubt that these little things are there for a reason.

What is a WAN-Port?

Wide Area Network is an acronym for Wide Area Network. A WAN-Port connects to the Internet. LAN (Local Area Network) ports connect to your computer and other devices, whereas the WAN (wide area network) ports need to be connected to your ISP's modem or the wall. By not connecting a cable to the WAN-port, your network will not be able to connect to the internet, and you won't be able to watch cute cat videos on YouTube or watch the latest episode of House of Cards on Netflix.

The quick answer was yes. However, as with anything else, there is always more to it, and today I thought we could take a look at WANs, LANs, and what you can do with the port on the back of your router.

The Difference Between LAN and WAN

First, you should know the difference between LAN and WAN, since both of these terms will be on the router. On the back of a router, there are five network ports, four of which are marked LAN and one is marked WAN.

LAN stands for Local Area Network and refers to a network of computers that are connected to each other. There is a LAN in your apartment or house. Every private network is a LAN. You can share resources in a LAN, such as printers or files, or you can connect to other computers or devices. Everything behind your router is a LAN.

Wide Area Network is an acronym for Wide Area Network. WANs can be either private or public, so it is more complicated. Many companies use private WANs to link their offices. Every office could have a LAN that shares printers and other devices locally, but a WAN that connects all the LANs together, so the company can share files.

The WAN connects LANs over the internet, and since no business wants unencrypted traffic flowing over the internet, they use VPN tunnels to establish secure connections between LANs. When a VPN (Virtual Private Network) tunnel is configured at both locations, the traffic through the tunnel is private and unauthorized users cannot view it.

If you're a home user, WAN doesn't have to be so complicated. It's more of a way to get the internet into your house and to your router. In my previous post, I described how companies connect their smaller offices to HQ via WAN, while for home users it's much the same, but for ISPs (Internet Service Providers). By connecting LANs from home users to their WAN, the ISP gives all LANs access to the network.

ISPs do not join LANs together, they keep them separate. Your neighbor cannot see your files or print from your printer.

Why a Router is Essential for WAN-Connections

We have covered the WAN-port on the back of the router, which is the outgoing connection to the internet. Your router will route all internet traffic through this port, both incoming and outgoing. All traffic goes through a single port, so all packages appear the same on other servers and devices on the internet. This means that whatever device you use outside the network will have the same IP address.

Whenever a package comes back to that IP address (your assigned IP address by your ISP), it's your router's job to identify which device made the request and forward that package to that device. In essence, the router sends the packages that come from the WAN-port to different LAN-ports or over the wireless network.

By skipping the router and connecting your ISP directly to your computer, only that computer would have internet access, no other devices. The same applies if you were to use a switch as a router, since a switch isn't made to translate incoming and outgoing packages to the internet.

When NOT to Use the WAN-Port

There are times when your router's WAN-port should not be used. For whatever reason, you may need to connect a second router to the same network. It is usually due to the fact that you have purchased your own router while your ISP also offers a router. It's very important not to use the WAN-port on the second router, as it wouldn't share the LAN with them. If you want to connect a device inside your LAN, you should use a LAN-port.

I highly suggest that you take a look at my guide on how to connect two routers, which you can find here, if you are interested in learning more about connecting two routers together.

Do Not Confuse WAN with WLAN

There is a common misconception that WAN stands for Wireless Area Network. People are well aware of what LAN is and that it stands for Local Area Network since LAN has been such a common (well, not very uncommon) word since the 90s and early 2000s when friends got together to play games. Wireless comes to mind when hearing WAN, which is understandable.

As you now know, this is completely incorrect. There is no such thing as a Wireless Area Network. It is a Wireless Local Area Network. Therefore, if you are already familiar with LAN, you can simply add a W to it when discussing wireless. This shouldn't be difficult. It would mix up WLAN and WAN, which would lead to very interesting conversations...

Can You Use the WAN-Port as a LAN-Port?

Sometimes, when the WAN-port is not being used (like when you have a second router and are instead using the LAN-port), it would be nice to use it as a LAN-port instead. Although I agree that it would be nice, it is not possible. The ports look the same, but their functions are completely different.

In order to get more LAN ports, you should instead purchase a switch. Switches give you extra LAN ports that you can use for your devices. You can find the Netgear GS105 on Amazon, which requires no configuration. I have three of these switches in my apartment.