This is a copy of a post I made at Medium.com, an experiment in distribution and exposure. It wasn’t very successful, so I’ve brought it back home to my blog.

Dear Mom, here’s why you need a guest wifi network

Edit: This is a generic post from a generic geek to a generic mom, although it does happen apply to mine ;)

Hey Mom - I’m going to suggest a primary benefit for a guest wifi network, which has nothing to do with technology. But you need to understand the technology first.

Background

You know how you have wifi at home? Your netbook, tablet, and smartphone are always online at home because of it? Your wifi network has a name, like Linksys (if you never changed it), “TB3820” (if it was pre-setup by your ISP), or “GrannyPad” (if you or the installer got tricky). All your gadgets connect to your wifi network by name (and the password, which you may or may not know!)

Guest Networks

Many wifi routers will let you create a second wifi network specifically for guests. A guest network works just like your normal network, but with two important differences:

Guest networks have a different name (and password) to the normal network
Users on the guest network can’t access the normal network

If these seems like unnecessary complexity, consider the following: Some of your devices are vulnerable You have a netbook, a tablet, and a smartphone, and they’re often not up-to-date because they’re either too old, or they’re used too infrequently, or you just don’t get around to it. (Dad has an even older smartphone which doesn’t get updated!)

Some of your things are exploitable

Maybe in the future you’ll buy a Chromecast or an AppleTV, so that you can display photos / video on your TV. Maybe you’ll buy a cheap Chinese digital photo frame, which streams your Facebook photos. Whatever it is — it’s likely that at some stage you’ll have technology permanently connected to wifi, which will default to trusting anything else connected to your wifi. I.e., devices that assume that sharing a wifi connection indicates implicit trust.

Not all of your guests are trustworthy

Maybe you invite some of your science students around to work on a project — they’ll ask for the wifi password for access for their gadgets. Maybe you trust these students, but do you trust who they will share the password with? Do you trust that their equipment is not vulnerable?

Technical benefits for a guest network

Technically, what does a guest network do to address the issues above?

Disposable guest wifi password

When your students ask for wifi access — give them the guest password. If you decide to revoke access, just change the guest password. You don’t have to reconfigure any of your devices. (You should do this periodically anyway, to ensure that there are no long-term “digital squatters”)

Keep the precious stuff secure

Now your guests have the internet access they need, without exposing any over-sharing devices, or providing the ability to stream media to your TV, or play with the digital photo frame.

Psychological benefit for a guest network

This is the real reason to do guest wifi, but the technical benefits above are necessary to appreciate it: A guest wifi network frees you to be generous. Make a one-time decision to spend 30 minutes setting up a guest network. Every time after that, when you’re asked for wifi access, you are free to be generous and give away the password without the mental effort of making a subjective decision about how trustworthy the guest is, and what risks you’re exposing yourself to.