Hello friends.
I am looking to obtain better WIFI Signal strength at my office building.
The Router is TP Link WDR 4300.

I am confused as to what kind of antennas are the OEM ones on that modem?
The Modem supports both 2.4 Ghz & 5 Ghz. There are 3 antennas. Does it mean each antenna support both 2.4 & 5? if not which ones are for 2.4 & which ones for 5ghz?

What I am trying to do is connect high gain YAGI antennas to atleast 2 of these ports to focus some signal on far end of building (in 2 directions). So which antenna ports do I choose?

I do not mind signal strength near the router itself.