GetIpForwardTable2 (Compact 2013)

3/26/2014

This function retrieves the IP route entries on the local device.

Syntax

NETIOAPI_API GetIpForwardTable2(
  __in   ADDRESS_FAMILY  Family,
  __out  PMIB_IPFORWARD_TABLE2* Table
);

Parameters

• 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.

  The header file organization 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 IP routing table that contains 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 IP routing table that contains only IPv4 entries.
  AF_INET6 23	The IP version 6 (IPv6) address family. When this parameter is specified, this function returns the IP routing table that contains only IPv6 entries.

• Table
  A pointer to a MIB_IPFORWARD_TABLE2 structure that contains a table of IP route entries on the local device.

Return Value

Return code	Description
NO_ERROR	The function succeeds.
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 IP route 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 GetIpForwardTable2 function enumerates the IP route entries on a local system and returns this information in a MIB_IPFORWARD_TABLE2 structure.

The IP route entries are returned in a MIB_IPFORWARD_TABLE2 structure in the buffer pointed to by the Table parameter. The MIB_IPFORWARD_TABLE2 structure contains an IP route entry count and an array of MIB_IPFORWARD_ROW2 structures for each IP route 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_IPFORWARD_TABLE2 structure pointed to by the Table parameter may contain padding for alignment between the NumEntries member and the first MIB_IPFORWARD_ROW2 array entry in the Table member of the MIB_IPFORWARD_TABLE2 structure. Padding for alignment may also be present between the MIB_IPFORWARD_ROW2 array entries. Any access to a MIB_IPFORWARD_ROW2 array entry should assume padding may exist.

See Also

Reference

IP Helper Functions
CreateIpForwardEntry2
DeleteIpForwardEntry2
FreeMibTable
GetBestRoute2
GetIpForwardEntry2
InitializeIpForwardEntry
MIB_IPFORWARD_ROW2
MIB_IPFORWARD_TABLE2
NotifyRouteChange2
SetIpForwardEntry2