Firewall behaviour is strange on one of my systems

[Gordon Messmer]

On 10/28/2015 03:17 PM, Antonio M wrote:
> still I have not done a single step to improve situation

The problem isn't obvious.  Your firewall rules are set up properly to 
both browse other mDNS devices and advertise services on your system 
using mDNS.

Maybe install the avahi-tools package and run "avahi-browse --all" in a 
terminal.  See what you get.