GetMulticastIpAddressTable function (netioapi.h)

The GetMulticastIpAddressTable function retrieves the multicast IP address table on the local computer.

Syntax

IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API GetMulticastIpAddressTable(
  [in]  ADDRESS_FAMILY                Family,
  [out] PMIB_MULTICASTIPADDRESS_TABLE *Table
);

Parameters

[in] Family

The address family to retrieve.

Possible values for the address family are listed in the Winsock2.h header file. Note that the values for the AF_ address family and PF_ protocol family constants are identical (for example, AF_INET and PF_INET), so either constant can be used.

On the Windows SDK released for Windows Vista and later, the organization of header files has changed and possible values for this member are defined in the Ws2def.h header file. Note that the Ws2def.h header file is automatically included in Winsock2.h, and should never be used directly.

The values currently supported are AF_INET, AF_INET6, and AF_UNSPEC.

Value Meaning
AF_UNSPEC
0
The address family is unspecified. When this parameter is specified, this function returns the multicast IP address table containing both IPv4 and IPv6 entries.
AF_INET
2
The Internet Protocol version 4 (IPv4) address family. When this parameter is specified, this function returns the multicast IP address table containing only IPv4 entries.
AF_INET6
23
The Internet Protocol version 6 (IPv6) address family. When this parameter is specified, this function returns the multicast IP address table containing only IPv6 entries.

[out] Table

A pointer to a MIB_MULTICASTIPADDRESS_TABLE structure that contains a table of anycast IP address entries on the local computer.

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 a NULL pointer is passed in the Table parameter or the Family parameter was not specified as AF_INET, AF_INET6, or AF_UNSPEC.
ERROR_NOT_ENOUGH_MEMORY
Insufficient memory resources are available to complete the operation.
ERROR_NOT_FOUND
No anycast IP address entries as specified in the Family parameter were found.
ERROR_NOT_SUPPORTED
The request is not supported. This error is returned if no IPv4 stack is on the local computer and AF_INET was specified in the Family parameter. This error is also returned if no IPv6 stack is on the local computer and AF_INET6 was specified in the Family parameter. This error is also returned on versions of Windows where this function is not supported.
Other
Use FormatMessage to obtain the message string for the returned error.

Remarks

The GetMulticastIpAddressTable function is defined on Windows Vista and later.

The
GetMulticastIpAddressTable function enumerates the multicast IP addresses on a local system and returns this information in a MIB_MULTICASTIPADDRESS_TABLE structure.

The multicast IP address entries are returned in a MIB_MULTICASTIPADDRESS_TABLE structure in the buffer pointed to by the Table parameter. The MIB_MULTICASTIPADDRESS_TABLE structure contains a multicast IP address entry count and an array of MIB_MULTICASTIPADDRESS_ROW structures for each multicast IP address entry. When these returned structures are no longer required, free the memory by calling the FreeMibTable.

The Family parameter must be initialized to either AF_INET, AF_INET6, or AF_UNSPEC.

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

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Target Platform Windows
Header netioapi.h (include Iphlpapi.h)
Library Iphlpapi.lib
DLL Iphlpapi.dll

See also

FreeMibTable

GetMulticastIpAddressEntry

MIB_MULTICASTIPADDRESS_ROW

MIB_MULTICASTIPADDRESS_TABLE