Enabling background scans for access points

In order to identify other access points within the device's local radio range, access points and wireless routers can record the beacons received (management frames) and store them in the scan table. Since this recording occurs in the background in addition to the access points' 'normal' radio activity, it is called a "background scan". Wireless routers in access-point mode normally use the background scan function for rogue AP detection. Without the background scan activated, the rogue detection in WLANmonitor is limited to the detection of rogue clients.

When configuring the background scan, you specify a time period in which all available WLAN channels are scanned once for the receiving beacons. The following tutorial describes how to set this time.

Start LANconfig and open the manual configuration dialog for your device.
In the dialog Wireless LAN > General, click Physical WLAN settings. and select the WLAN interface for which the background scanning is to be enabled.
In the dialog window that opens, navigate to the Radio tab.
Select a time unit in the selection list Background scan unit and enter a corresponding duration in the input field Background scan interval.

This scan interval should correspond to the time span within which rogue access points should be recognized, e.g. 3600 seconds. The minimum meaningful value in both the 2.4-GHz and the 5-GHz bands is 260 seconds. In the case of 13 possible channels, this value prompts another channel to be scanned each 20 seconds (interval/number of channels).
Close all of the dialogs and write the configuration back to the device.

That's it! From now on, at the specified scan interval your WLAN device cyclically searches the currently unused frequencies of the active band for available access points.