IPV6 address on wifi I noticed the other day that my Android phone (Moto X first gen running lollipop) was reporting having an IPv6 address. 

After a bit of investigation I discovered two things


It only shows when connected to WiFi, not cellular data. 
The address it is showing is a loop back address starting fe80:


I am a bit bemused as to why this is. Why would it be enabling IPv6 and why would it be reporting it's address is a loop back address?
fe80: isn't a loopback address, it's a link-local address.  Every IPv6-enabled network interface has one, and it's in addition to any global ("real") IPv6 addresses that the interface may (or may not) have.  What you're seeing is entirely normal and expected; it just means that your phone supports IPv6 on WiFi.  (Presumably, IPv6 is enabled so that the phone can take advantage of it on networks that actually provide IPv6 Internet connectivity.)

The IPv6 loopback address is ::1.  You'll probably see that address on the lo interface, along with the IPv4 127.0.0.1 loopback address.