Because my internet connection is very unstable at the moment, I'd like to use a small indicator applet for the Unity panel.
Since I'm connected through a WLAN/Wifi Router, I can see in the network-applet when the connection to the router is lost, but not when the router loses the connection to the Internet.
A Windows 7 computer of mine has this functionality. It shows a black exclamation mark on yellow ground if it can't "ping" a remote server.
I'm running Ubuntu 11.10 "Oneiric Ocelot" 64-Bit with Unity 3D.
Whilst you mentioned you wish to do this in the network applet - I don't think you can do this. Here is an alternative.
internet up
internet down
how to for 11.10 & 12.04
It requires an indicator from a PPA together with a custom ping test script:
using:
Copy and paste the code below into the new file and save & close.
Give the file execute permission:
Start the indicator
Then in the indicator-preferences:
click "use this command" and copy and paste the following text:
code
The original answer was written for Ubuntu 11.10 & 12.04.
Since then, the indicator interface was changed for 12.10 & 13.04. However, the maintainer has not released a version since then for later Ubuntu versions. No code commits in the launchpad PPA has been made since first quarter 2013.
Thus I have forked the project, fixed a few bugs and made it available for 14.04 Trusty users. Feel free to check out the code on GitHub and help out with the maintenance.
internet up
internet down
how to for 14.04
It requires an indicator from my PPA together with a custom ping test script:
using:
Copy and paste the code below into the new file and save & close.
Give the file execute permission:
Start the indicator
Then in the indicator-preferences click New:
Then enter the details as shown:
i.e. use the command
Click OK, followed by the following actions 1,2,3 & 4:
code