The capture options

Before starting a capture, set the options in the Capture Options dialog to tune capture buffer performance for your network analysis needs. Set these options carefully to make sure that the packets you need are still available in the buffer for postcapture analysis when you have finished capturing data (as shown in Figure 4-2).

Figure 4-2. The capture options

Netwalk capture option The capture options

As shown in Figure 4-2, you can set the following:

  • Buffer Size
  • Capture Filter
  • Auto Save
  • Other Options

Buffer Size

The Buffer Size option specifies how much memory AthTek NetWalk uses for captured packets. AthTek NetWalk supports large buffer sizes, up to 256M.

Capture Filter

The Filter area in the Settings tab lets you select a filter to apply to a capture session. Capture filters limit which packets are stored in the capture buffer, providing you with the means of focusing the capture on just that data which interests you.

If a filter is currently selected, the name of that filter is displayed in the Filter area. To deselect that filter, click the Remove button. The filter name will then be replaced by None to indicate that no filter currently applies. The name of the button changes to Set to indicate that you can set (select) a new filter.

If you click on the Set button, the Filter List dialog box (Figure 4-3) appears. You can then choose the filter you want from the list of currently defined filters.

Figure 4-3. The filter picker dialog

Netwalk filter picker The capture options

You can create a new filter in Filter Manager. For details on how to create new filters (or edit existing filters) see Using Filters.

Auto Save

The Auto Save feature lets you automatically save trace files when the capture buffer becomes full. The options are:

  • By default, Auto Save is Disabled. If you want to enable Auto Save, click the Enable check box.
  • In the File path box, type in the directory name where you want to save your files.
  • File Prefix is the first part of the name for the trace files you want to save. The default is auto_.
  • File Count limits the number of files auto saved, and a number sequence will be added to each trace file.

Other Options

The Other options area provides the following additional settings that help you to optimize performance versus features while capturing.

  • If the Disable monitor during capture box is checked, the operation of the Monitor will be paused when a capture starts, and will resume when the capture stops.
  • If the Show this dialog when starting capture box is not checked, the Capture Option dialog will not showup when starting new capture session, and the last capture options will be used.

The capture options