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GetIfTable2Ex (Compact 7)

  • Article

3/12/2014

This function retrieves the MIB-II interface table.

Syntax

NETIOAPI_API GetIfTable2Ex(
  __in   MIB_IF_TABLE_LEVEL Level,
  __out  PMIB_IF_TABLE2* Table
);

Parameters

  • Level
    The level of interface information to retrieve. This parameter can be one of the values from the MIB_IF_TABLE_LEVEL enumeration type that is defined in the Netioapi.h header file.

    Value Meaning

    MibIfTableNormal

    The values of statistics and state returned in members of the MIB_IF_ROW2 structure in the MIB_IF_TABLE2 structure pointed to by the Table parameter are returned from the top of the filter stack when this parameter is specified.

    MibIfTableRaw

    The values of statistics and state returned in members of the MIB_IF_ROW2 structure in the MIB_IF_TABLE2 structure pointed to by the Table parameter are returned directly for the interface being queried.
  • Table
    A pointer to a buffer that receives the table of interfaces in a MIB_IF_TABLE2 structure.

Return Value

If the function succeeds, the return value is NO_ERROR.

If the function fails, the return value is one of the following error codes.

Return code Description

ERROR_INVALID_PARAMETER

An invalid parameter was passed to the function. This error is returned if an illegal value was passed in the Level parameter.

ERROR_NOT_ENOUGH_MEMORY

Insufficient memory resources are available to complete the operation.

Other

Use FormatMessage to obtain the message string for the returned error.

Remarks

The GetIfTable2Ex function enumerates the logical and physical interfaces on a local system and returns this information in a MIB_IF_TABLE2 structure. GetIfTable2Ex is an enhanced version of the GetIfTable function that allows selecting the level of interface information to retrieve.

A similar GetIfTable2 function can also be used to retrieve interfaces. but does not allow specifying the level of interfaces to return. Calling the GetIfTable2Ex function with the Level parameter set to MibIfTableNormal retrieves the same results as calling the GetIfTable2 function.

Interfaces are returned in a MIB_IF_TABLE2 structure in the buffer pointed to by the Table parameter. The MIB_IF_TABLE2 structure contains an interface count and an array of MIB_IF_ROW2 structures for each interface. Memory is allocated by the GetIfTable2 function for the MIB_IF_TABLE2 structure and the MIB_IF_ROW2 entries in this structure. When these returned structures are no longer required, free the memory by calling the FreeMibTable.

All interfaces including NDIS intermediate driver interfaces and NDIS filter driver interfaces are returned for either of the possible values for the Level parameter. The setting for the Level parameter affects how statistics and state members of the MIB_IF_ROW2 structure in the MIB_IF_TABLE2 structure pointed to by the Table parameter for the interface are returned. For example, a network interface card (NIC) will have a NDIS miniport driver. An NDIS intermediate driver can be installed to interface between upper-level protocol drivers and NDIS miniport drivers. An NDIS filter driver (LWF) can be attached on top of the NDIS intermediate driver. Assume that the NIC reports the MediaConnectState member of the MIB_IF_ROW2 structure as MediaConnectStateConnected but NDIS filter driver modifies the state and reports the state as MediaConnectStateDisconnected. When the interface information is queried with Level parameter set to MibIfTableNormal, the state at the top of the filter stack, that is MediaConnectStateDisconnected is reported. When the interface is queried with the Level parameter set to MibIfTableRaw, the state at the interface level directly, that is MediaConnectStateConnected is returned.

Note that the returned MIB_IF_TABLE2 structure pointed to by the Table parameter may contain padding for alignment between the NumEntries member and the first MIB_IF_ROW2 array entry in the Table member of the MIB_IF_TABLE2 structure. Padding for alignment may also be present between the MIB_IF_ROW2 array entries. Any access to a MIB_IF_ROW2 array entry should assume padding may exist.

See Also

Reference

IP Helper Functions
FreeMibTable
GetIfTable
GetIfTable2
MIB_IF_TABLE2
MIB_IF_ROW2