Wednesday 2 November 2016

Apple iPhone 6 and above, WIFI and the mysterious connection problem

As you know, I use this page as a dumping ground for anything tech related which might come back to haunt me at some point.  Today's post concerns the wonderful iPhone, and a mysterious WIFI problem....

I have a WIFI network, with multiple Access Points, and two iPhones - a 5c and a 6s.  The 5c will connect to my wireless network, the 6s will not - it tries, but keeps prompting for a password, even when the correct one is used..  Both are running the same version of IOS (10.1.1), so why can't the 6s connect?

The answer appears to be one of two things.  Firstly, the WIFI network I created was using WPA2 ONLY (no fall back to standard WPA) - looks like the iPhone 6s didn't like that - once I configured WPA as the fallback protocol, I could connect - once.  After that initial connection, the WIFI would not connect again without doing a network reset in IOS - unacceptable of course, so a bit more digging was required.  It turns out that iPhones are a bit sensitive when roaming between access points, and if like me, you have multiple access points that overlap, this can cause a problem if mis-configured on the WIFI network.  On my network, I had to switch on the "layer 2 handover" parameter, which essentially allows roaming devices to use network layer 2 when negotiating roaming.  Once that was done, everything was fine.

For future reference....

Apple's recommended settings for access points...
Cisco's WIFI recommendations for Apple devices (PDF)...