CreateSortedAddressPairs function (netioapi.h)

Article
10/13/2021

The CreateSortedAddressPairs function takes a supplied list of potential IP destination addresses, pairs the destination addresses with the host machine's local IP addresses, and sorts the pairs according to which address pair is best suited for communication between the two peers.

Syntax

IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API CreateSortedAddressPairs(
  [in, optional] const PSOCKADDR_IN6 SourceAddressList,
  [in]           ULONG               SourceAddressCount,
  [in]           const PSOCKADDR_IN6 DestinationAddressList,
  [in]           ULONG               DestinationAddressCount,
  [in]           ULONG               AddressSortOptions,
  [out]          PSOCKADDR_IN6_PAIR  *SortedAddressPairList,
  [out]          ULONG               *SortedAddressPairCount
);

Parameters

[in, optional] SourceAddressList

Must be NULL. Reserved for future use.

[in] SourceAddressCount

Must be 0. Reserved for future use.

[in] DestinationAddressList

A pointer to an array of SOCKADDR_IN6 structures that contain a list of potential IPv6 destination addresses. Any IPv4 addresses must be represented in the IPv4-mapped IPv6 address format which enables an IPv6 only application to communicate with an IPv4 node.

[in] DestinationAddressCount

The number of destination addresses pointed to by the DestinationAddressList parameter.

[in] AddressSortOptions

Reserved for future use.

[out] SortedAddressPairList

A pointer to store an array of SOCKADDR_IN6_PAIR structures that contain a list of pairs of IPv6 addresses sorted in the preferred order of communication, if the function call is successful.

[out] SortedAddressPairCount

A pointer to store the number of address pairs pointed to by the SortedAddressPairList parameter, if the function call is successful.

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 the DestinationAddressList, SortedAddressPairList, or SortedAddressPairCount parameters NULL, or the DestinationAddressCount was greater than 500. This error is also returned if the SourceAddressList is not NULL or the SourceAddressPairCount parameter is not zero.
ERROR_NOT_ENOUGH_MEMORY	Not enough storage is available to process this command.
ERROR_NOT_SUPPORTED	The request is not supported. This error is returned if no IPv6 stack is on the local computer.
Other	Use FormatMessage to obtain the message string for the returned error.

Remarks

The CreateSortedAddressPairs function is defined on Windows Vista and later.

The CreateSortedAddressPairs function takes a list of source and destination IPv6 addresses, and returns a list of pairs of addresses in sorted order. The list is sorted by which address pair is best suited for communication between the source and destination address.

The list of source addresses pointed to by the SourceAddressList is currently reserved for future and must be a NULL pointer. The SourceAddressCount is currently reserved for future and must be zero. The CreateSortedAddressPairs function currently uses all of the host machine's local addresses for the source address list.

The list of destination addresses is pointed to by the DestinationAddressList parameter. The list of destination addresses is an array of SOCKADDR_IN6 structures. Any IPv4 addresses must be represented in the IPv4-mapped IPv6 address format which enables an IPv6 only application to communicate with an IPv4 node. For more information on the IPv4-mapped IPv6 address format, see Dual-Stack Sockets. The DestinationAddressCount parameter contains the number of destination addresses pointed to by the DestinationAddressList parameter. The CreateSortedAddressPairs function supports a maximum of 500 destination addresses.

If the CreateSortedAddressPairs function is successful, the SortedAddressPairList parameter points to an array of SOCKADDR_IN6_PAIR structures that contain the sorted address pairs. When this returned list is no longer required, free the memory used by the list by calling the FreeMibTable function.

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