CreateIpForwardEntry2 function (netioapi.h)
The CreateIpForwardEntry2 function creates a new IP route entry on the local computer.
Syntax
IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API CreateIpForwardEntry2(
[in] const MIB_IPFORWARD_ROW2 *Row
);
Parameters
[in] Row
A pointer to a MIB_IPFORWARD_ROW2 structure entry for an IP route entry.
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 |
|---|---|
|
Access is denied. This error is returned under several conditions that include the following: the user lacks the required administrative privileges on the local computer or the application is not running in an enhanced shell as the built-in Administrator (RunAs administrator). |
|
An invalid parameter was passed to the function. This error is returned if a NULL pointer is passed in the Row parameter, the DestinationPrefix member of the MIB_IPFORWARD_ROW2 pointed to by the Row parameter was not specified, the NextHop member of the MIB_IPFORWARD_ROW2 pointed to by the Row parameter was not specified, or both the InterfaceLuid or InterfaceIndex members of the MIB_IPFORWARD_ROW2 pointed to by the Row parameter were unspecified. This error is also returned if the PreferredLifetime member specified in the MIB_IPFORWARD_ROW2 is greater than the ValidLifetime member or if the SitePrefixLength in the MIB_IPFORWARD_ROW2 is greater than the prefix length specified in the DestinationPrefix. |
|
The specified interface could not be found. This error is returned if the network interface specified by the InterfaceLuid or InterfaceIndex member of the MIB_IPNET_ROW2 pointed to by the Row parameter could not be found. |
|
The request is not supported. This error is returned if the interface specified does not support routes. This error is also returned if no IPv4 stack is on the local computer and AF_INET was specified in the address family in the DestinationPrefix member of the MIB_IPFORWARD_ROW2 pointed to by the Row parameter. This error is also returned if no IPv6 stack is on the local computer and AF_INET6 was specified for the address family in the DestinationPrefix member. |
|
The object already exists. This error is returned if the DestinationPrefix member of the MIB_IPFORWARD_ROW2 pointed to by the Row parameter is a duplicate of an existing IP route entry on the interface specified by the InterfaceLuid or InterfaceIndex member of the MIB_IPFORWARD_ROW2. |
|
Use FormatMessage to obtain the message string for the returned error. |
Remarks
The CreateIpForwardEntry2 function is defined on Windows Vista and later.
The CreateIpForwardEntry2 function is used to add a new neighbor IP address entry on a local computer. The InitializeIpForwardEntry function should be used to initialize the members of a MIB_IPFORWARD_ROW2 structure entry with default values. An application can then change the members in the MIB_IPFORWARD_ROW2 entry it wishes to modify, and then call the CreateIpForwardEntry2 function.
The DestinationPrefix member in the MIB_IPFORWARD_ROW2 structure pointed to by the Row parameter must be initialized to a valid IPv4 or IPv6 address prefix. The NextHop member in the MIB_IPFORWARD_ROW2 structure pointed to by the Row parameter must be initialized to a valid IPv4 or IPv6 address and family. In addition, at least one of the following members in the MIB_IPFORWARD_ROW2 structure pointed to the Row parameter must be initialized to the interface: the InterfaceLuid or InterfaceIndex.
The fields are used in the order listed above. So if the InterfaceLuid is specified, then this member is used to determine the interface on which to add the IP route entry. If no value was set for the InterfaceLuid member (the values of this member was set to zero), then the InterfaceIndex member is next used to determine the interface.
The route metric offset specified in the Metric member of the MIB_IPFORWARD_ROW2 structure pointed to by Row parameter represents only part of the complete route metric. The complete metric is a combination of this route metric offset added to the interface metric specified in the Metric member of the MIB_IPINTERFACE_ROW structure of the associated interface. An application can retrieve the interface metric by calling the GetIpInterfaceEntry function.
The Age and Origin members of the MIB_IPFORWARD_ROW2 structure pointed to by the Row are ignored when the CreateIpForwardEntry2 function is called. These members are set by the network stack and cannot be set using the CreateIpForwardEntry2 function.
The CreateIpForwardEntry2 function will fail if the DestinationPrefix and NextHop members of the MIB_IPFORWARD_ROW2 pointed to by the Row parameter are a duplicate of an existing IP route entry on the interface specified in the InterfaceLuid or InterfaceIndex members.
The CreateIpForwardEntry2 function can only be called by a user logged on as a member of the Administrators group. If CreateIpForwardEntry2 is called by a user that is not a member of the Administrators group, the function call will fail and ERROR_ACCESS_DENIED is returned. This function can also fail because of user account control (UAC) on Windows Vista and later. If an application that contains this function is executed by a user logged on as a member of the Administrators group other than the built-in Administrator, this call will fail unless the application has been marked in the manifest file with a requestedExecutionLevel set to requireAdministrator. If the application lacks this manifest file, a user logged on as a member of the Administrators group other than the built-in Administrator must then be executing the application in an enhanced shell as the built-in Administrator (RunAs administrator) for this function to succeed.
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 |