CreateProxyArpEntry function

The CreateProxyArpEnry function creates a Proxy Address Resolution Protocol (PARP) entry on the local computer for the specified IPv4 address.


DWORD CreateProxyArpEntry(
  _In_ DWORD dwAddress,
  _In_ DWORD dwMask,
  _In_ DWORD dwIfIndex


dwAddress [in]

The IPv4 address for which this computer acts as a proxy.

dwMask [in]

The subnet mask for the IPv4 address specified in dwAddress.

dwIfIndex [in]

The index of the interface on which to proxy ARP for the IPv4 address identified by dwAddress. In other words, when an ARP request for dwAddress is received on this interface, the local computer responds with the physical address of this interface. If this interface is of a type that does not support ARP, such as PPP, then the call fails.

Return value

The function returns NO_ERROR (zero) if the function is successful.

If the function fails, the return value is one of the following error codes.

Return codeDescription

Access is denied. This error is returned on Windows Vista and Windows Server 2008 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 input parameter is invalid, no action was taken. This error is returned if the dwAddress parameter is zero or an invalid value, one of the other parameters is invalid.


The IPv4 transport is not configured on the local computer.


Use FormatMessage to obtain the message string for the returned error.



To retrieve the ARP table, call the GetIpNetTable function. To delete an existing PARP entry, call the DeleteProxyArpEntry .

On Windows Vista and later, the CreateProxyArpEnry function can only be called by a user logged on as a member of the Administrators group. If CreateProxyArpEnry 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 on Windows Vista and later 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.

Note  This function executes a privileged operation. For this function to execute successfully, the caller must be logged on as a member of the Administrators group or the NetworkConfigurationOperators group.


Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]







See also

IP Helper Start Page
IP Helper Function Reference