Network Monitor is a small utility to help you monitor the status of your Internet connection. It keeps track of your connection status verifying that you can reach an external reliable server.
Network Monitor stays on your menu bar and can notify you via Notification Center as well as by talking when your status changes. Both can be turned off via menu bar.
It also keeps track of a log of all your connection status in logs (accesible via your Console application) if you ever have to show connection stability.
Privacy note:
There are NO information sent from your computer to that external server aside from your current IP address.