INT SetOption(
	DWORD dwOption,
	BOOL bEnabled
);

The SetOption method is used to enable or disable a specific socket option.

Parameters

dwOption

An unsigned integer used to specify one of the socket options. These options cannot be combined. The following values are recognized:

Constant	Description
INET_OPTION_BROADCAST	This option specifies that broadcasting should be enabled for datagrams. This option is invalid for stream sockets.
INET_OPTION_KEEPALIVE	This option specifies that packets are to be sent to the remote system when no data is being exchanged to keep the connection active. This is only valid for stream sockets.
INET_OPTION_REUSEADDRESS	This option specifies the local address can be reused. This option is commonly used by server applications.
INET_OPTION_NODELAY	This option disables the Nagle algorithm, which buffers unacknowledged data and insures that a full-size packet can be sent to the remote host.

bEnabled

A boolean flag. If the flag is set to a non-zero value, the option is enabled. Otherwise the socket option is disabled.

Return Value

If the method succeeds, the return value is zero. If the method fails, the return value is INET_ERROR. To get extended error information, call GetLastError.

Remarks

It is not recommend that you disable the Nagle algorithm by specifying the INET_OPTION_NODELAY flag unless it is absolutely required. Doing so can have a significant, negative impact on the performance of the application and network.

If if the INET_OPTION_KEEPALIVE option is enabled, keep-alive packets will start being generated five seconds after the socket has become idle with no data being sent or received. Enabling this option can be used by applications to detect when a physical network connection has been lost. However, it is recommended that most applications query the remote host directly to determine if the connection is still active. This is typically accomplished by sending specific commands to the server to query its status, or checking the elapsed time since the last response from the server.

Requirements

Minimum Desktop Platform: Windows 7 (Service Pack 1)
Minimum Server Platform: Windows Server 2008 R2 (Service Pack 1)
Header: Include cswsock10.h
Import Library: cswskv10.lib

See Also

Connect, GetOption

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