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Monthly Archives: August 2015

How to fix network service discovery disabled

It looks like avahi-daemon is started when the network connection is established (


). 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):


Better one:

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


sudo gedit /etc/NetworkManager/NetworkManager.conf
sudo service network-manager restart

How to fix GPG or KEYEXPIRED error in ubuntu

If you have been using ibus-avro for a while, you may have encourtered this error when running apt-get update.

W: GPG error: http://download.opensuse.org ./ Release: The following signatures were invalid: KEYEXPIRED 1366357218

Lets see how to fix that.

  1. Open Ubuntu Software Center.
  2. From Top bar goto Edit > Software Sources
  3. Goto Authentication Tab and select the sarimkhan OBS Project key.
  4. Press Remove and confirm by entering your password.
  5. Now open up terminal and add the correcponding key for your OS, for example ubuntu 13.04
  6.  wget -q http://download.opensuse.org/repositories/home:/sarimkhan/xUbuntu_13.04/Release.key -O- | sudo apt-key add -
  7. Now you can update your software sources without any problem.
  8.  sudo apt-get update
  9. Have Fun and keep rocking.

If the command are not doing it for you, you have to do it on your own. After a long research on this problem i finally decided that the best thing to do was manually download the key and add it.This is how i did it. Go to Ubuntu Key-server(Click here). Here you can search your key. In my case it was 6AF0E1940624A220. Note while searching for key pre-append the key with 0x. So search for 0x6AF0E1940624A220

Click on the link provided in the pub section. Copy the whole text(highlighted in below screen shot) from the page and save it in a file(say filename is key1)

Once you have copied the data to file. Save it. Then run the following command

 sudo apt-key add key1

You will get an “OK” response.

And you are done. Repeat the procedure of other keys that might be missing. Then you can run sudo

apt-get update

and you will not get any error. Update happens smoothly. Do let me know if you still have any doubts.