Earlier this week, I had a problem with my iPhone at home. It was showing as connected to Wifi, but I couldn’t get web pages to load. It turns out that my iPhone was connected to a different network: BT Wifi with FON, rather than our own network.
This is a side-effect of having a BT Home Hub, which is that it broadcasts multiple SSIDs. One is the encrypted one for your use. The other is a public one, without access to your home computers, that anyone can use (the BT Wifi with FON network).
Essentially the iPhone – and presumably other iOS devices like the iPad and iPod Touch – rank available wifi networks alphabetically. It will automatically connect to the first one that you’ve used previously. In the screenshot, if I’d connected to all three before, then the iPhone would default to ‘_The Cloud’. This is despite ‘eduroam’ being a secure network and not an open one. This presumably explains why The Cloud, and other public Wifi providers, have started prefixing their networks with underscores.
You can tap the blue arrow and then select ‘Forget this network’ to tell your iPhone not to connect automatically in future. But the next time you use this network your phone will resume automatic connections.
To date, Apple hasn’t included a way to rank networks on iOS, like it does on OS X. So I can’t tell my iPhone to connect to ‘eduroam’ in favour of ‘_The Cloud’ if both are available, but still have it automatically connect to ‘_The Cloud’ if ‘eduroam’ isn’t available.
There is, however, a workaround, which is detailed in How to Prioritize Wifi Networks on Your iPhone? on NooTrix. You will need to use Apple’s iPhone Configuration Utility, which is available for Mac OS X and Windows. This allows you to create a configuration profile which tells your iPhone to always connect to a preferred Wifi network, even if another one that you’ve used previously is available. You then send the profile to the phone using the USB cable.
Note that if you have used The Cloud’s Wifi FastConnector or BT Wifi apps you may already have profiles saved which will tell your iPhone to prefer these networks as well. In which case, you may wish to delete them. You’ll still be able to use these wifi networks without the profiles but your iPhone won’t be so keen to connect to them automatically.