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•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 page17 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.