SetIpInterfaceEntry function

The SetIpInterfaceEntry function sets the properties of an IP interface on the local computer.

Syntax

IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API SetIpInterfaceEntry(
  PMIB_IPINTERFACE_ROW Row
);

Parameters

Row

A pointer to a MIB_IPINTERFACE_ROW structure entry for an interface. On input, the Family member of the MIB_IPINTERFACE_ROW must be set to AF_INET6 or AF_INET and the InterfaceLuid or the InterfaceIndex member of the MIB_IPINTERFACE_ROW must be specified. On a successful return, the InterfaceLuid member of the MIB_IPINTERFACE_ROW is filled in if InterfaceIndex member of the MIB_IPINTERFACE_ROW entry was specified.

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_ACCESS_DENIED
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).
ERROR_FILE_NOT_FOUND
The system cannot find the file specified. This error is returned if the network interface LUID or interface index specified by the InterfaceLuid or InterfaceIndex member of the MIB_IPINTERFACE_ROW pointed to by the Row parameter was not a value on the local machine.
ERROR_INVALID_PARAMETER
An invalid parameter was passed to the function. This error is returned if a NULL pointer is passed in the Row parameter, the Family member of the MIB_IPINTERFACE_ROW pointed to by the Row parameter was not specified as AF_INET or AF_INET6, or both the InterfaceLuid or InterfaceIndex members of the MIB_IPINTERFACE_ROW pointed to by the Row parameter were unspecified.
ERROR_NOT_FOUND
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_IPINTERFACE_ROW pointed to by the Row parameter does not match the IP address family specified in the Family member in the MIB_IPINTERFACE_ROW structure.
Other
Use FormatMessage to obtain the message string for the returned error.

Remarks

The SetIpInterfaceEntry function is defined on Windows Vista and later.

The SetIpInterfaceEntry function can is used to modify an existing IP interface entry.

On input, the Family member in the MIB_IPINTERFACE_ROW structure pointed to by the Row parameter must be initialized to either AF_INET or AF_INET6. In addition on input, at least one of the following members in the MIB_IPINTERFACE_ROW structure pointed to the Row parameter must be initialized: the InterfaceLuid or InterfaceIndex.

The fields are used in the order listed above. So if the <b>InterfaceLuid</b> is specified, then this member is used to determine the interface. If no value was set for the  <b>InterfaceLuid</b> member (the values of this member was set to zero), then the <b>InterfaceIndex</b> member is next used to determine the interface. 

On output, the InterfaceLuid member of the MIB_IPINTERFACE_ROW structure pointed to by the Row parameter is filled in if the InterfaceIndex was specified.

The MaxReassemblySize, MinRouterAdvertisementInterval, MaxRouterAdvertisementInterval , Connected, SupportsWakeUpPatterns, SupportsNeighborDiscovery, SupportsRouterDiscovery, ReachableTime, TransmitOffload, and ReceiveOffload members of the MIB_IPINTERFACE_ROW structure pointed to by the Row are ignored when the SetIpInterfaceEntry function is called. These members are set by the network stack and cannot be changed using the SetIpInterfaceEntry function.

An application would typically call the GetIpInterfaceTable function to retrieve the IP interface entries on the local computer or call the GetIpInterfaceEntry function to retrieve just the IP interface entry to modify. The MIB_IPINTERFACE_ROW structure for the specific IP interface entry could then be modified and a pointer to this structure passed to the SetIpInterfaceEntry function in the Row parameter. However for IPv4, an application must not try to modify the SitePrefixLength member of the MIB_IPINTERFACE_ROW structure. For IPv4, the SitePrefixLength member must be set to 0.

Another possible method to modify an existing IP interface entry is to use InitializeIpInterfaceEntry function to initialize the fields of a MIB_IPINTERFACE_ROW structure entry with default values. Then set the Family member and either the InterfaceIndex or InterfaceLuid members in the MIB_IPINTERFACE_ROW structure pointed to by the Row parameter to match the IP interface to change. An application can then change the fields in the MIB_IPINTERFACE_ROW entry it wishes to modify, and then call the SetIpInterfaceEntry function. However for IPv4, an application must not try to modify the SitePrefixLength member of the MIB_IPINTERFACE_ROW structure. For IPv4, the SitePrefixLength member must be set to 0. Caution must be used with this approach because the only way to determine all of the fields being changed would be to compare the fields in the MIB_IPINTERFACE_ROW of the specific IP interface entry with fields set by the InitializeIpInterfaceEntry function when a MIB_IPINTERFACE_ROW is initialized to default values.

Unprivileged simultaneous access to multiple networks of different security requirements creates a security hole and allows an unprivileged application to accidentally relay data between the two networks. A typical example is simultaneous access to a virtual private network (VPN) and the Internet. Windows Server 2003 and Windows XP use a weak host model, where RAS prevents such simultaneous access by increasing the route metric of all default routes over other interfaces. Thus all traffic is routed through the VPN interface, disrupting other network connectivity.

On Windows Vista and later, a strong host model is used by default. If a source IP address is specified in the route lookup using GetBestRoute2 or GetBestRoute, the route lookup is restricted to the interface of the source IP address. The route metric modification by RAS has no effect as the list of potential routes does not even have the route for the VPN interface thereby allowing traffic to the Internet. The DisableDefaultRoutes member of the MIB_IPINTERFACE_ROW can be used to disable using the default route on an interface. This member can be used as a security measure by VPN clients to restrict split tunneling when split tunneling is not required by the VPN client. A VPN client can call the SetIpInterfaceEntry function to set the DisableDefaultRoutes member to TRUE when required. A VPN client can query the current state of the DisableDefaultRoutes member by calling the GetIpInterfaceEntry function.

The

The SetIpInterfaceEntry function can only be called by a user logged on as a member of the Administrators group. If SetIpInterfaceEntry 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

   
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

GetBestRoute

GetBestRoute2

GetIfEntry2

GetIfTable2

GetIfTable2Ex

GetIpInterfaceEntry

GetIpInterfaceTable

IP Helper Function Reference

InitializeIpInterfaceEntry

MIB_IF_ROW2

MIB_IF_TABLE2

MIB_IPINTERFACE_ROW

MIB_IPINTERFACE_TABLE

NotifyIpInterfaceChange