Here is a step-by-step guide for using an Airport Express to create a private wireless network in your house that is separate from your primary one.

I’m a good AirBnB host in Berlin and I want to provide internet access for my guests but do no also want to give them access to my servers and other devices on my home network. So how do we go about doing that?

After a lot of research and testing I am sharing these steps, because I did not find a simple online tutorial that walks non-technical people through the process.

I am also using a very common and cheap device to provide this service – an Apple Airport Express.

An airport Express is a small white box that you can plug an Ethernet cable into and transmit a private network. They are common, durable and user friendly. I bought mine off of eBay for about $50.

The internet arrives to my house from my provider via a box that has a modem, LAN switch and wi-fi router inside of it.

The key thing to look for is the presence of LAN ethernet ports. These are jacks that you can plug internet devices into and have them available on your home network.

Maybe your internet box only has one port? If that is the case, you will need to multiply that port by adding an ethernet switch. A “switch” is a low-cost device and simple to set up.
Here is what that configuration might look like this when attached to your cable modem.

The key thing to remember is this. Once you plug in a device to a LAN port or logon to the wi-fi of this network, all of your gadgets can share the internet and can see and talk to each other by default. That’s a good thing when we want our Apple TV to talk to our iPhone and our iTunes to play music to all of our wireless speakers.

But it’s not always so great to share your primary network with your visitors. Security and privacy are the primary reasons to give them access to the internet, but not see any of your devices.

So how do we create a new, isolated network without having to purchase another internet account from our provider and set up another box, etc?

I am sharing a simple method. We have to create a “subnet” that creates wireless access to the internet for our guests and bypasses access to our main home network entirely.

And to do that we will plug in our little Airport Express into one of the LAN ports and configure it like this.

1. Attach your Airport Express to a LAN port.
2. Launch Airport Express utility and enter the key settings in the screens below.

From the setup menu select “Create a Wireless network” and “WPA personal.”

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Give your guest wi-fi network a name and a password will you will issue for guests

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From connection sharing, select “Share a public IP address” from the drop-down menu.

Under the DHCP tab, enter these numbers. This is the critical step to creating a subnet. Your guests will be accessing the Internet from a different and uniques set of IP addresses from your primary network.

Your Airport Express will tell you there is a problem creating Double NAT’s.

This is normal. It is telling you that there are now two, separate networks running from your internet connection point.

That’s what you want.

You can tell the Airport Express to ignore this problem.

When you are finished entering these setting click the update button and your new, private wireless network will be up and running for your guests to enjoy.