C# Definition:

/// <summary>
    /// Contains the numbers for the current LAN adapters.
    /// </summary>
    public struct LANA_ENUM
    {
    /// <summary>
    /// Specifies the number of valid entries in the array of LAN adapter numbers.
    /// </summary>
    public byte[] length;

    /// <summary>
    /// Specifies an array of LAN adapter numbers.
    /// </summary>
    [System.Runtime.InteropServices.MarshalAs(
        System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst = 255)]
    public byte[] lana;
    }

VB Definition:

Private Const NCBENUM As Integer = &H37
Private Const MAX_LANA As Integer = 254

<StructLayout(LayoutKind.Sequential)> _
Private Structure LANA_ENUM
   Dim length As Byte
   <MarshalAs(UnmanagedType.ByValArray, SizeConst:=MAX_LANA + 1)> Dim lana() As Byte
End Structure

User-Defined Field Types:

None.

Notes:

/*
  *  Structure returned to the NCB command NCBENUM.
  *
  *  On a system containing lana's 0, 2 and 3, a structure with
  *  length =3, lana[0]=0, lana[1]=2 and lana[2]=3 will be returned.
  */

typedef struct _LANA_ENUM {
   UCHAR   length;     //  Number of valid entries in lana[]
   UCHAR   lana[MAX_LANA+1];
} LANA_ENUM, *PLANA_ENUM;