•DHCP server discovery—This feature uses DHCP option 43 to provide controller IP addresses to the access points. Cisco switches support a DHCP server option that is typically used for this capability. For more information about DHCP option 43, see the “Configuring DHCP Option 43 and DHCP Option 60” section on page 40.
•DNS discovery—The access point can discover controllers through your domain name server (DNS). For the access point to do so, you must configure your DNS to return controller IP addresses in response to CISCO-CAPWAP-CONTROLLER.localdomain, where localdomain is the access point domain name. Configuring the CISCO-CAPWAP-CONTROLLER provides backwards compatibility in an existing customer deployment. When an access point receives an IP address and DNS information from a DHCP server, it contacts the DNS to resolve CISCO-CAPWAP-CONTROLLER.localdomain. When the DNS sends a list of controller IP addresses, the access point sends discovery requests to the controllers.
Preparing the Access Point
Before you mount and deploy your access point, we recommend that you perform a site survey (or use the site planning tool) to determine the best location to install your access point.
You should have the following information about your wireless network available:
•Access point locations.
•Access point mounting options: below a suspended ceiling, on a flat horizontal surface, or on a desktop.
Note You can mount the access point above a suspended ceiling but you must purchase additional mounting hardware: See “Mounting the Access Point” section on page 17 for additional information.
•Access point power options: power supplied by the recommended external power supply (Cisco AIR-PWR-B), a DC power supply, PoE from a network device, or a PoE power injector/hub (usually located in a wiring closet).
Note Access points mounted in a building’s environmental airspace must be powered using PoE to comply with safety regulations.
Cisco recommends that you make a site map showing access point locations so that you can record the device MAC addresses from each location and return them to the person who is planning or managing your wireless network.
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