Configuring the service

The service features can be changes using the NMapWin GUI. Go to the Service tab on the main page. This will bring you to the service configuration page:

The service settings page is divided into several fields. On top of the page is the weekday selection, than the interval and start time selection and finally the interval period. The settings you see om the screenshot above will scan the network each Sunday at 01:00:00.

Current setting

The current setting is stored in two parameter fields in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NMap\Parameters\NMapArgs

and

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NMap\Parameters\NMapServArgs

NMapArgs contains all nmap related parameters and NMapServArgs all nmap service related parameters. NMapArgs contains per default: -sS -PI -PT, whereas NMapServArgs contains: 01:00:00 24 3 0 1 1 1 1 1 1 0 0 per default. See Registry Keys for more details on this keys.

Both parameters can be retrieved using the Get Param button of the NMapWin service page. Using the Set Param button will store the current settings in the registry. The service can be started/stopped using the two buttons Start and Stop.

Weekday selection

Select the weekdays you want to scan your network by selecting the corresponding checkboxes on top of the service settings page. In case the selected interval (see interval setting is more than one day, the nmap process will only start on days which are selected here. For example, if you select every second day for scanning, and the next scan day is not selected in the weekday selection, this day is skipped and the next scan will be performed 2 days later (assuming that this is selected in the weekday selection).

Interval selection

The scan interval (the period of time between two consecutive scans) is determined by the interval factor and the interval period. The interval factor can be Hours, Days, Weeks or Month. Depending on the selected factor the interval slider is changing the minumum and maximum scale. In case you select Days as interval factor the slider min, max values will be 0 to 30 (one month).

The interval can be set using the slider or the corresponding text box. The PageUp, PageDown as well as the Left and Right buttons are supported. PageUp and PageDown will change the value in intervals max/5, whereas Left and Right are changing the values with a stepsize of 1.

Start date/time

The start date/time can be selected using the two tect boxes in the middle of the tab. The date field will open a calendar in which one can select the start date for the first scan. The time is selected using the up and down buttons, or by editing the box directly.

Options

AutoStart starts scanning after service starts. If set to ON the service will start scanning the network. This flag is written to the registry using the Set Param button. The service will retrieve a notification event and will execute the change immediately. In case Immediately is also 'ON' one scan job will start immediately, otherwise the service will wait for the next scan interval (see below).
Immediately will start one scan job immediately, regardless the current interval setting.

After installation the AutoStart is set to 'OFF'. Therefore the service will not start any scan job until the AutoStart flag is set to 'ON'. The change is propagated to the service immediately. Nevertheless, depending on the Immediately flag setting, the start of the next scan job could be delayed until the next scan time.

Registry keys

The registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NMap\Parameters\NMapArgs

and

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NMap\Parameters\NMapServArgs

are used to store the current setting of the NMap service. The syntax of the NMapArgs key is exactly identical to the nmap command line arguments. See the NMap manual page for more information on the different command line arguments.

The NMapServArgs syntax is:

Start time: the start time as HH:MM:SS.
Interval factor: the interval factor as 0:hour, 1:days, 2: weeks, 3: month.
Scan interval: the scan interval in units determined by the interval factor.
Week day selection: seven integers 0: OFF, 1: ON, first index is Sunday: 0.

In case the registry keys are changed using a registry editor, the new values will be automatically before the next scan starts.