Hi,

   Trying to enumerate interfaces on RRAS.
   Bellow is what I have so far. The MprAdminInterfaceEnum has an
lplpbBuffer out parameter which is a buffer that will contain an array of
MPR_INTERFACE_0's.
   I want to access the wszInterfaceName for each interface. How should I
marshal this parameter?

Thanks,
Juan

/// <summary>
 /// The MprAdminInterfaceEnum function enumerates all the interfaces on a
specified server.
 /// </summary>
 /// <param name="hMprServer">[in] Handle to the router on which to execute
this call. Obtain this handle by calling MprAdminServerConnect.</param>
 /// <param name="dwLevel">[in] Specifies the level of information passed
in lpBuffer. Must be zero.</param>
 /// <param name="lplpbBuffer">[out] Pointer to a pointer variable that
points to an array of MPR_INTERFACE_0 structures on successful return. This
memory must be freed by a call to the MprAdminBufferFree function.</param>
 /// <param name="dwPrefMaxLen">[in] Specifies the preferred maximum length
of returned data (in 8-bit bytes). If this parameter is -1, the buffer
returned is large enough to hold all available information. </param>
 /// <param name="lpdwEntriesRead">[out] Pointer to a DWORD variable. This
variable receives the total number of interfaces that were enumerated from
the current position in the enumeration.</param>
 /// <param name="lpdwTotalEntries">[out] Pointer to a DWORD variable. This
variable receives the total number of interfaces that could have been
enumerated from the current resume position.</param>
 /// <param name="lpdwResumeHandle">[in] Pointer to a DWORD variable. This
variable specifies a resume handle that can be used to continue the
enumeration. The handle should be zero on the first call, and left unchanged
on subsequent calls. If the return code is ERROR_MORE_DATA then the call can
be re-issued using the handle to retrieve more data. If on return, the
handle is NULL, the enumeration cannot be continued. For other types of
error returns, this handle is invalid.
 /// This parameter is optional. If the calling application specifies NULL
for this parameter, the function does not return a resume handle.</param>
 /// <returns></returns>
 /// <remarks><code>
 /// DWORD APIENTRY
 /// MprAdminInterfaceEnum(
 ///     IN      MPR_SERVER_HANDLE       hMprServer,
 ///     IN      DWORD                   dwLevel,
 ///     OUT     LPBYTE *                lplpbBuffer,
 ///     IN      DWORD                   dwPrefMaxLen,
 ///     OUT     LPDWORD                 lpdwEntriesRead,
 ///     OUT     LPDWORD                 lpdwTotalEntries,
 ///     IN      LPDWORD                 lpdwResumeHandle        OPTIONAL
 /// );
 /// </code></remarks>
 [DllImport("Mprapi.dll", CharSet = CharSet.Ansi)]
 public static extern int MprAdminInterfaceEnum(
  IntPtr hMprServer,
  [MarshalAs(UnmanagedType.U4)]
     int dwLevel,

     ref MPR_INTERFACE_0[] lplpbBuffer,
     int dwPrefMaxLen,
  ref int lpdwEntriesRead,
  ref int lpdwTotalEntries,
  ref int lpdwResumeHandle
  );

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct MPR_INTERFACE_0
{
 [MarshalAs(UnmanagedType.ByValTStr, SizeConst =
MprApi.MAX_INTERFACE_NAME_LEN+1)]
 public string wszInterfaceName;
 public IntPtr hInterface;
 public bool fEnabled;
 public ROUTER_INTERFACE_TYPE dwIfType;
 public ROUTER_CONNECTION_STATE dwConnectionState;
 public UnreachabilityReasons fUnReachabilityReasons;
 public int dwLastError;
}