Cisco WIRELESS LAN CONTROLLER OL-17037-01 - Manual (Page 25)

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Cisco Wireless LAN Controller Configuration Guide
OL-17037-01
Chapter 7 Controlling Lightweight Access Points
Autonomous Access Points Converted to Lightweight Mode
Using DHCP Option 43 and DHCP Option 60
Cisco Aironet access points use the type-length-value (TLV) format for DHCP option 43. DHCP servers
must be programmed to return the option based on the access point’s DHCP Vendor Class Identifier
(VCI) string (DHCP Option 60).
Table 7-1 lists the VCI strings for Cisco access points capable of
operating in lightweight mode.
This is the format of the TLV block:
• Type: 0xf1 (decimal 241)
• Length: Number of controller IP addresses * 4
• Value: List of the IP addresses of controller management interfaces
Refer to the product documentation for your DHCP server for instructions on configuring DHCP option
43. The Upgrading Autonomous Cisco Aironet Access Points to Lightweight Mode document contains
example steps for configuring option 43 on a DHCP server.
Troubleshooting the Access Point Join Process
Access points can fail to join a controller for many reasons: a RADIUS authorization is pending,
self-signed certificates are not enabled on the controller, the access point and controller’s regulatory
domains do not match, and so on.
Controller software release 5.2 enables you to configure the access points to send all CAPWAP-related
errors to a syslog server. You do not need to enable any debug commands on the controller because all
of the CAPWAP error messages can be viewed from the syslog server itself.
The state of the access point is not maintained on the controller until it receives a CAPWAP join request
from the access point. Therefore, it can be difficult to determine why the CAPWAP discovery request
from a certain access point was rejected. In order to troubleshoot such joining issues without enabling
CAPWAP debug commands on the controller, the controller collects information for all access points
that send a discovery message to this controller and maintains information for any access points that have
successfully joined this controller.
The controller collects all join-related information for each access point that sends a CAPWAP discovery
request to the controller. Collection begins with the first discovery message received from the access
point and ends with the last configuration payload sent from the controller to the access point.
Table 7-1 VCI Strings For Lightweight Access Points
Access Point VCI String
Cisco Aironet 1130 Series Cisco AP c1130
Cisco Aironet 1140 Series Cisco AP c1140
Cisco Aironet 1200 Series Cisco AP c1200
Cisco Aironet 1240 Series Cisco AP c1240
Cisco Aironet 1250 Series Cisco AP c1250
Cisco AP801 Embedded Access Point Cisco AP801