Network service discovery disabled: What does this mean for me?

It looks like avahi-daemon is started when the network connection is established (/etc/network/if-up.d/avahi-daemon). This notification is informing you that mDNS (Avahi) has been disabled. It's only used for a small number of applications that only work on the local network, it won't adversely affect your internet connection or DNS.

The most well known use for mDNS is sharing music with Rhythmbox (or iTunes) over your LAN. It's an Apple technology, but it's largely been ignored in favour of uPNP or DLNA.

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

Source: http://ubuntuforums.org/showthread.php?t=1632952

According to the Avahi wiki there are two workarounds:

Better one:

In /etc/avahi/avahi-daemon.conf uncomment and change the line with domain name to

domain-name=.alocal

Second one:

In /etc/nsswitch.conf delete a [NOTFOUND=return] text.

It probably says that Avahi is disabled because you have a .local domain and Avahi doesn't work very well with this.

Avahi is a zero conf protocol like Apples Bonjour commonly used if you have Macs on your network or if you want to chat with others on your local network without logging in to a server like Google Talk or MSN Messenger.

You can read about the problem here.

You could probably just ignore it or configure your network to use another domain name then the default .local.