public static extern int GetAdaptersInfo(IntPtr pAdapterInfo, ref Int64 pBufOutLen);

<DllImport("iphlpapi.dll", EntryPoint:="GetAdaptersInfo", CharSet:=CharSet.Ansi)> _

Private Shared Function GetAdaptersInfo( _

     Dim ret As Int32 = GetAdaptersInfo(pArray, len)

     ret = GetAdaptersInfo(pArray, len)

   int ret = GetAdaptersInfo( pArray, ref structSize );

     ret = GetAdaptersInfo( pArray, ref structSize );

     throw new InvalidOperationException( "GetAdaptersInfo failed: " + ret );

GetAdaptersInfo returns a pointer to an IP_ADAPTER_INFO linked list.

Use GetAdaptersInfo to determine which adapter the index corresponds to.