The Media Access Control addresses of all network adapters. Note that these values are the addresses loaded from the driver, and thus could have been set by the user. Having two network cards with same MAC connected to the same physical network segment will lead into trouble. Usually MAC addresses are burned into the PROM of a NIC, so this is no problem unless someone changes his MAC deliberately (for example) to bypass access restrictions.

public static string[] MacAddresses { get; }