internet connection

Test for what?

What problem are you having exactly?

We don't have much information at all about your network.

But, if you are using a modem, the first troubleshooting step would normally be to connect your computer directly to the modem for a day or two using a wired Ethernet cable connection and check the connection quality from time to time. If you suspect that you might be having a problem with your computer, then test using another computer for a day or so to watch the connection that way....and compare the results with your other computer.

If the connection drops during your "test" with one computer......but not the other......then this indicates that you may likely have a problem with the computer. If the connection drops with both computers, you likely either have a problem with the Internet wiring and signal coming into your house.....or.....with the modem itself.

It would help if you could tell us more about your modem.....make and model number.....your AirPort router model.....assuming that you have one, how you normally connect.....wired or wireless, etc.

Basically, you should assume that we don't really know anything about your network (we don't), so the extent of what we will know about your issue will be the result of what you can tell us.

As it stands now, we have no idea at all what the issue might be.

I'd have to agree with Bob. Taking as many things out of the equation as possible is always a good idea. Connecting your computer directly to your modem and testing the internet connection is a good starting point. And telling us more about your current network setup will also help.

Other than that, you may want to try Ookla's speedtest at http://www.speedtest.net.

If your internet connection is unstable, it will show it in the graph. You want a more or less uniform speed through out the test.