I have added a Netgear WiFi Extender as I was having problems connecting devices in a corner of my home [NOTE: I am not endorsing the Netgear extender, I purchased it from Amazon because it got good reviews and, because it is from Amazon, can be returned!].
I was confused about the interaction of the extender's Proxy ARP with the router's ARP, the relaying of information and -- this was the most confusing -- the "jumping / switching" of the extender's virtual MAC ID [yes, extenders use virtual MAC IDs, not their physical MAC IDs.].
It was interesting -- at least to me -- research which lead to the creation of i) the below macro and ii) a +/- 15 page document detailing the interaction of the extender, the extender's virtual MAC IDs, the router, the network monitoring consequences, and more.
The Keyboard Maestro macro monitors the devices that are connected to the extender's 2.4GHz radio and the extender's 5.0 GHz radio. The macro spawns two terminal windows that are centred horizontally and vertically on the left monitor (assuming two displays. else the main monitor) and refresh every 5 seconds.
Thought I would share in case anyone else is interested noting I can also share the document I built as well, just let me know.
