The following figure provides an example of a wireless network.

A station or wireless client is any wireless-capable device that can connect to an AP using a wireless signal.

Dynamic Channel Selection (DCS) is a feature that allows an AP to automatically select the radio channel which it broadcasts. For more information, see Technical Reference.

Use this screen to manage the Zyxel Device’s general wireless settings.

 

Use this screen to enable Rogue AP Detection and import/export a rogue or friendly AP list in a txt file.

A rogue AP is a wireless access point operating in a network’s coverage area that is not under the control of the network administrator, and which can potentially open up holes in a network’s security.

In the following example, a corporate network’s security is compromised by a rogue AP (RG) set up by an employee at his workstation in order to allow him to connect his notebook computer wirelessly (A). The company’s legitimate wireless network (the dashed ellipse B) is well-secured, but the rogue AP uses inferior security that is easily broken by an attacker (X) running readily available encryption-cracking software. In this example, the attacker now has access to the company network, including sensitive data stored on the file server (C).

If you have more than one AP in your wireless network, you should also configure a list of “friendly” APs. Friendly APs are wireless access points that you know are not a threat. It is recommended that you export (save) your list of friendly APs often, especially if you have a network with a large number of access points. Exported lists show MAC addresses in txt file format separated by line breaks.

This feature allows the Zyxel Device to monitor the WiFi signals for other wireless APs (see also Radio Frequency (RF) Monitor). Detected APs will appear in the Monitor > Wireless > Detected Device screen, where the Zyxel Device will label APs with the criteria you select in Suspected Rogue AP Classification Rule as a suspected rogue. The APs which you mark as either rogue or friendly APs in the Monitor > Wireless > Detected Device screen will appear in the Wireless > Rogue AP screen. See Zyxel Device Product Feature to know which models support Rogue AP Detection.

 

 

Use this screen to configure dynamic radio channel selection (see Dynamic Channel Selection (DCS)).

 

The following section contains additional technical information about the features described in this chapter.

When numerous APs broadcast within a given area, they introduce the possibility of heightened radio interference, especially if some or all of them are broadcasting on the same radio channel. If the interference becomes too great, then the network administrator must open his AP configuration options and manually change the channel to one that no other AP is using (or at least a channel that has a lower level of interference) in order to give the connected stations a minimum degree of interference. Dynamic channel selection frees the network administrator from this task by letting the AP do it automatically. The AP can scan the area around it looking for the channel with the least amount of interference.

In the 2.4 GHz spectrum, each channel from 1 to 13 is broken up into discrete 22 MHz segments that are spaced 5 MHz apart. Channel 1 is centered on 2.412 GHz while channel 13 is centered on 2.472 GHz.

Three channels are situated in such a way as to create almost no interference with one another if used exclusively: 1, 6 and 11. When an AP broadcasts on any of these 3 channels, it should not interfere with neighboring APs as long as they are also limited to same trio.

However, some regions require the use of other channels and often use a safety scheme with the following four channels: 1, 4, 7 and 11. While they are situated sufficiently close to both each other and the three so-called “safe” channels (1,6 and 11) that interference becomes inevitable, the severity of it is dependent upon other factors: proximity to the affected AP, signal strength, activity, and so on.

Finally, there is an alternative four channel scheme for ETSI, consisting of channels 1, 5, 9, 13. This offers significantly less overlap that the other one.