ESP8266 nodemcu resolving raspberry's local dns

问题

I'm having an issue with connecting the esp module on the raspberry via mqtt. After a lot of search I think I am kinda lost now.

So here's the problem

I have setup my raspberry's local dns to work as cubex.local, I followed the instructions here:

http://www.howtogeek.com/167190/how-and-why-to-assign-the-.local-domain-to-your-raspberry-pi/

Everything seems to be working fine on this end...
I can use the cubex.local on the local network to have ssh and ftp access to the raspberry but when it comes to the esp trying to resolve that address it keeps failing.

this is the code running on the esp:

function broker_connect()
 m = mqtt.Client(ID, 120, BRUSER, BRPWD)
 m:on("message", on_message_received)
 m:on("connect", on_connect)
 m:on("offline", on_mqqt_offline)

 tmr.alarm(0, 1000, 1,function() 
 print("Connecting to MQTT broker at "..HOST..". Please wait...")
 m:connect( HOST , PORT, 0)
end)

and the output:

Connecting to MQTT broker at cubex.local. Please wait...
DNS retry 1!
DNS retry 2!
DNS retry 3!
DNS retry 4!
DNS Fail!
Connecting to MQTT broker at cubex.local. Please wait...
DNS retry 1!
DNS retry 2!
DNS retry 3!
DNS retry 4!
DNS Fail!
Connecting to MQTT broker at cubex.local. Please wait...
DNS retry 1!
DNS retry 2!
DNS retry 3!
DNS retry 4!
DNS Fail!

The host variable holds the cubex.local and the port is 1883.
When I use the raspberry's IP which is 192.168.0.3 everything works fine.
Still I fail to understand why it keeps failing to resolve the address.