解決
http://askubuntu.com/questions/339702/network-service-discovery-disabled-what-does-this-mean-for-me/339709#339709
To disable it, you must edit the file /etc/default/avahi-daemon
as root:
sudo -i
gedit /etc/default/avahi-daemon
and add this line (or change it if already exists to):
AVAHI_DAEMON_DETECT_LOCAL=0