Cisco IW3702 Getting Started Manual page 35

Cisco IW3702 Access Point Getting Started Guide
Configuration
The Controller Discovery Process
The access point uses standard Control and Provisioning of Wireless Access Points Protocol (CAPWAP) to communicate
between the controller and other wireless access points on the network. CAPWAP is a standard, interoperable protocol
that allows an access controller to manage a collection of wireless termination points. The discovery process using
CAPWAP is identical to the Lightweight Access Point Protocol (LWAPP) used with Cisco IW3702 access points.
LWAPP-enabled access points are compatible with CAPWAP, and conversion to a CAPWAP controller is seamless.
Deployments can combine CAPWAP and LWAPP software on the controllers.
The functionality provided by the controller does not change, except for customers who have Layer 2 deployments, which
CAPWAP does not support.
In a CAPWAP environment, the wireless access point discovers a controller by using CAPWAP discovery mechanisms
and then sends it a CAPWAP join request. The controller sends the access point a CAPWAP join response to allow the
access point to join the controller. When the access point joins the controller, the controller manages its configuration,
firmware, control transactions, and data transactions.
For additional information about the discovery process and CAPWAP, see the
Configuration Guide.

Notes: Refer to the Release Notes for the Cisco IW3702 access points for the minimum required Cisco Wireless
LAN Controller software release.

You cannot edit or query any access point using the controller CLI if the name of the access point contains
a space.

Ensure that the controller is set to the current time. If the controller is set to a time that has already
occurred, the access point might not join the controller because its certificate may not yet be valid.
Access points must be discovered by a controller before they can become active in the network. The access point
supports these controller discovery processes:

Layer 3 CAPWAP discovery—Can occur on different subnets than the access point and uses IP addresses and UDP
packets rather than MAC addresses used by Layer 2 discovery.

Locally stored controller IP address discovery—If the access point was previously joined to a controller, the IP
addresses of the primary, secondary, and tertiary controllers are stored in the access point's non-volatile memory.
This process of storing controller IP addresses on an access point for later deployment is called priming the access
point. See Performing a Pre-Installation Configuration, page

DHCP server discovery—This feature uses DHCP option 43 to provide controller IP addresses to access points. Cisco
switches support a DHCP server option that is typically used for this capability. See
DHCP Option 60, page

DNS discovery—The access point can discover controllers through your domain name server (DNS). To use this
discovery method, you must configure the 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 backward compatibility in an existing deployment. When an access
point receives the 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.
Performing a Pre-Installation Configuration
The following procedures ensure a successful access point installation and initial operational setup. Pre-installation
configuration – priming the access point – is optional.
Note: If your network controller already properly configured, you can skip priming and simply install your access point in
its final location and connect it to the network. See
38.
Deploying in a Wireless Network, page
Cisco Wireless LAN Controller Software
35.
35
Configuring DHCP Option 43 and
39.