This post will explain the “Guest” notion in a Wi-Fi network and how to use that properly.
To cut to the chase: A Guest Wi-Fi network is a special Internet-only SSID for short-term use. While it’s a handy feature, it’s not intended as a security measure, and using it for your own devices can cause unexpected issues.
Dong’s note: I first published this piece on July 8, 2020, and last updated it on August 3, 2026, with the latest relevant information.
What is a Guest Wi-Fi network?
A Guest Wi-Fi network is a type of virtual SSID designed for a visitor-based network that’s isolated from the primary one you use for your home. In a router, the primary network is often referred to as your intranet.
Isolation is the keyword here.
Specifically, a device connected to a router’s Guest Wi-Fi network, by default, has access to the Internet and nothing else. Specifically, it’s not part of the router’s primary network and, therefore, can’t reach any local resources, such as shared folders on a server, a network printer, or any other devices.
But we need to get something straight: There’s no such thing as “Guest” in networking. The name is a marketing term for a readily available isolated virtual SSID that users can turn on or off in most routers made for the home.
That said, not all routers have the Guest Wi-Fi feature. Instead, in advanced SMB or enterprise-class routers, the ability to set an SSID to keep its connected client isolated is a common feature.
So, device isolation is what you’re looking for in all cases. “Guest” is just a fancy name created for the home.
The purpose of this isolation is to give short-term devices access to the Internet while keeping them from accessing the local resources that don’t concern their users.
How to set up a Guest Wi-Fi network
Again, any (Wi-Fi) network that keeps connected devices separated (isolated) from your primary network is a “guest” network. And there are a few ways to achieve this.
Turn it on
On a home Wi-Fi router, Guest Wi-Fi is as easy as turning it on. You’ll find this feature in a section called “Guest Network”, “Guest Access”, or something to that effect.
Once turned on, the Guest network is isolated by default, so make sure you don’t change this setting.
Tip
If you choose to make the Guest Wi-Fi network (SSID) have access to your primary network, a setting often labeled as “Intranet access”, then it’s simply another virtual SSID for your primary network. You can use it to segment your devices, but the isolation effect is no longer.
Most routers’ Guest Wi-Fi network feature comes with some other customization, including time access limit, bandwidth limit, etc. You can configure those or leave them alone, but it’s always a good idea to secure this network with a password — use a different one from that of your primary Wi-Fi.
By the way, the isolation of a Guest Wi-Fi applies to all connected devices, meaning not only can’t they access your intranet, but they also can’t see one another.
So, this type of Guest networking is suitable for temporary guests who need the Internet and nothing else. It’s also the right choice for a public place, like a coffee shop. But if you want to offer your guests more than just the Internet, this type of Guest networking won’t cut it. Instead, it would be best to have a separate intranet.
Create a separate intranet
If you want your guests living in the mother-in-law unit to feel even more welcome, you can equip the place with more gadgets, such as a network printer or a separate Wi-Fi audio system.
To keep these devices available to your guests yet separate from yours, you’ll need to build a different intranet for them.
There are many ways to do this, including using a feature called VLAN, which is available in SBM or high-end home routers. However, the easiest is to use a separate router (with a different Wi-Fi network) on top of your existing one in a double-NAT setup.
In this case, the guest intranet is separate from your primary network, but its devices are not isolated from one another. That’s important because most local devices require being on the same local area network (LAN) to work as intended.
And that brings us to how you shouldn’t use the Guest Wi-Fi network for your IoT devices simply for “security” reasons.
Guest Wi-Fi and your IoT devices
Considering the privacy aspects of the Guest Wi-Fi, a lot of folks believe this type of isolation is also great for “security” and use one for their smart devices.
However, keeping your device isolated is a double-edged sword: while they can’t access your local resources, your local resources can’t access these devices, either. And it’s important to note that IoT devices generally need intranet access to work as intended.
Take a network printer, for example. Hooking it to an isolated Guest Wi-Fi network will keep it invisible to your other devices — your computer or smartphone can’t see that printer to send it print jobs.
Similar things will happen with other devices, like Wi-Fi speakers or IP cameras. Putting them on the guest network means disconnecting them from your local network. Everything now has to go through the Internet, which is not always an option for locally managed devices.
Here are some more examples of what might not work if you connect your IoTs to an isolated Guest Wi-Fi network.
- You can’t wirelessly cast a computer’s or mobile device’s screen on your smart TV.
- Wi-Fi speakers won’t work.
- Network printers won’t work locally.
- Most IP cameras won’t work.
- Local movie streaming (from your server) won’t work.
The list goes on. So, to those wanting to put IoT devices on a Guest Wi-Fi network: Stop making it a standard practice!
While old (and off-brand) IoT devices might have security holes or use unsecured default passwords, modern ones are much better. In any case, make sure you secure yours with a good password during the setup process.
How about that IoT Wi-Fi network?
Nowadays, you’ll note that many Wi-Fi routers and access points have the option to create a virtual IoT SSID. Specifically, it’s a network in which the default name is formed by attaching the “IoT” suffix to the primary SSID. (Just like the Guest Wi-Fi SSID, you can change the name to your liking.)
The “IoT” SSID is not meant to be isolated. It’s simply a virtual SSID designed to segment your primary network, and the idea behind this practice makes sense.
Smart Wi-Fi devices are often low-power and require little bandwidth. Using them in a network can hinder the performance of other full-feature clients, such as computers, tablets, or smartphones.
That said, having a separate Wi-Fi SSID that uses low-performance settings or the 2.4GHz band for them will help keep your network optimal.
Most of the time, these “IoT” SSIDs use only the 2.4GHz band, though some can also use the 5GHz band, but they never use the 6GHz band.
Like the case of the Guest Wi-Fi, the “IoT” SSID is a convenience but not a special feature. You can simply create a 2.4GHz-only virtual SSID and use WPA2 security for it to get the same effect.
The takeaway
The main purpose of a Guest Wi-Fi network (SSID) is to keep connected devices isolated from the primary network for privacy and security reasons, designed specifically for short-term, temporary devices.
As such, it’s not intended to be the security feature for permanent, long-term devices on a network. Using isolation for your devices willy-nilly can create all sorts of unexpected issues.
The best way to keep your (IoT) devices safe from hacking is not to get cheap ones from unknown vendors. Then set a secure password for them and keep them on the latest firmware. On top of that, keep your router’s firmware up to date.
In any case, security is a matter of degrees. The only way to keep a device completely secure against online threats is to turn it off.
