Captive Portals

It’s 2023. It’d be really nice if wifi just worked. Alas, when we travel, that’s often not the case. We’ve all dealt with the frustration of a wifi network that just doesn’t seem to do anything, or works just enough to give you hope, but not quite enough to be useful. 

The reality is, often you’re out of luck. Free public wifi in places like airports – especially outside the US and east Asia – is often hopeless. However, there are one or two tech tips which can sometimes help.

Captive Wifi

Sometimes, when you connect to wifi in a hotel, airport, or coffee shop, a special website will popup. On Windows, it’ll open in your normal browser, whereas on MacOS and iOS devices, it’ll be a standalone popup window. Sometimes these pages will just ask you to agree to terms of service or enter a password, but you might also use them to purchase access. This popup is called a “captive portal,” because it intercepts traffic from your computer and forces you to see their page instead.

Sometimes though, especially when reconnecting to a wifi network you’ve used in the past (think at a hotel which requires you to reconnect each day), the captive portal website doesn’t appear. Instead, your wifi just does … nothing.

Fortunately, there’s an easy trick to reactivate a captive portal. You need to attempt to access a non-secure website in your normal browser. A non-secure website is one without the lock icon in your browser.

Fortunately for your security, but unfortunately for your wifi, most websites are secure by default these days. So, the tip is to remember, or even bookmark, This is a special server Apple runs just for the purpose of triggering captive portals. You can use it on your phone or laptop, whether or not it’s an Apple product. 

So, next time you connect to a wifi network and nothing seems to happen, try loading that address. 

Missing IP Addresses

Each time your device connects to a wifi network, it gets assigned a unique identifier or “IP address”. Or at least, it’s supposed to get assigned a unique address. This process can fail and leave your device unable to talk to the internet. This is probably the biggest hiccup I see with public wifi. 

There’s not much you can do in this case, but you can at least diagnose it by seeing which IP address your device is reporting. This is different for every type of device, but TheVerge has a nice explainer for each of the common platforms. All you need to remember is that IP addresses starting with “169” are bad – that’s basically a fake address that devices use when they can’t get a real one. 

If you see one of these addresses, there’s not much you can do, but sometimes a little patience can help. In many cases, the network itself is working ok, but the server that assigns addresses is having trouble. Your computer will keep trying as long as you leave it powered on and not sleeping. I’ve had it take up to 5 minutes to get an IP address assigned. 

When in Doubt, Tether

For anyone who needs to get work done while traveling, getting comfortable with tethering is a must. Tethering is when your computer or tablet uses your phone’s cellular connection to access the internet. Whether you’re using your normal cellular provider or you’ve purchased a local sim or eSIM, tethering is a great way to get online – and it’s often faster than wifi as well. 

Google has a nice guide for Android users, and Apple has one for iPhone users (Macs usually automatically prompt to tether when there’s no wifi as well).  Just be aware that tethering will draw down your data allowance just like browsing on your phone. Doing data intensive tasks like running cloud backup software or streaming movies can burn through your quota quickly. 

Remember That Website

The main reason I wrote this tip was to tell you about Bookmark it! Use it! 

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