Extender weirdness

I have a hatred for the app. 

I'd recommend logging into the router through the browser. Then you can check the attached devices list and see if they're on there. You can also access them using their IP address from this list. 

Its not abnormal to get <unknown> because the extender has to give the device connecting to it a virtual mac. 

This is the route I'd go and trust. Its always been the most accurate. 

One thing I'd advise with running more than 1 extender is make sure they're setup in a star configuration and not daisy chained. 

IE don't go router----->extender------>extender

Go Extender<-------router-------->extender

Those extenders take a 50% speed reduction because they can't broadcast/receive at the same time. So they cut the speed in half of what they receive. Add a second one after the first and its BEST case is its getting 25% of speed from the router. And that's best case because distance/interference/obstruction all reduce speed too.