1. Avoid Foreign AP interference: Enabled by default. When enabled the co-channel interference metric is included in DCA calculations. For 802.11a this is good to enable as there are multiple non overlapping channels to change. But in 802.11b/g there are only 3 non overlapping channels and always there will be co-channel interference. So you need to careful when to tick this box for b/g.
2. Avoid Cisco AP Load: Disabled by default. When enabled, the client load on an AP is taken into consideration before making a channel change. It is good idea to tick this in order to prevent channel change for large client AP.
3.Avoid Persistent Non-WiFi Interference： enable the Cisco WLC to ignore persistent non-WiFi interference.
4.In the DCA Channel List area, the DCA Channels text box shows the channels that are currently selected. To choose a channel, select its check box in the Select column. To exclude a channel, unselect its check box.
The ranges are as follows: 802.11a—36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 132, 136, 140, 149, 153,
157, 161, 165, 190, 196 802.11b/g—1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
The defaults are as follows: 802.11a—36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 132, 136, 140, 149, 153,
157, 161 802.11b/g—1, 6, 11
These extended UNII-2 channels in the 802.11a band do not appear in the channel list: 100, 104, 108, 112, 116, 132, 136, and 140. If you have Cisco Aironet 1520 series mesh access points in the -E regulatory domain, you must include these channels in the DCA channel list before you start operation. If you are upgrading from a previous release, verify that these channels are included in the DCA channel list. To include these channels in the channel list, select the Extended UNII-2 Channels check box.