Test for tunnel adapters

In my application I list all available network adapters...

Code:

---

..
foreach (NetworkInterface ni in NetworkInterface.GetAllNetworkInterfaces())
{
    //add it to UI combobox
}
..

---

As my app is now being used more and more on Win7, users complain that a lot of 'unknown' network adapters are listed.
It appears these are IPv6 so-called tunnel adapters .

Does anyone know of a way to programmatically detect wether NetworkInterface is such a tunnel adapter ?

Look at the NetworkInterfaceType property, and check it isn't 'Tunnel'