Cisco WIRELESS LAN CONTROLLER OL-17037-01 - Manual (Page 4)

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Cisco Wireless LAN Controller Configuration Guide
OL-17037-01
Chapter 7 Controlling Lightweight Access Points
Access Point Communication Protocols
• 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
“Using DHCP Option 43 and
DHCP Option 60” section on page 7-25 .
• 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-LWAPP-CONTROLLER.localdomain, where localdomain is the access point
domain name. When an access point receives an IP address and DNS information from a DHCP
server, it contacts the DNS to resolve CISCO-LWAPP-CONTROLLER.localdomain. When the DNS
sends a list of controller IP addresses, the access point sends discovery requests to the controllers.
Verifying that Access Points Join the Controller
When replacing a controller, you need to make sure that access points join the new controller.
Using the GUI to Verify that Access Points Join the Controller
Follow these steps to ensure that access points join the new controller.
Step 1 Follow these steps to configure the new controller as a master controller.
a. Click Controller > Advanced > Master Controller Mode to open the Master Controller
Configuration page.
b. Check the Master Controller Mode check box.
c. Click Apply to commit your changes.
d. Click Save Configuration to save your changes.
Step 2 (Optional) Flush the ARP and MAC address tables within the network infrastructure. Ask your network
administrator for more information about this step.
Step 3 Restart the access points.
Step 4 Once all the access points have joined the new controller, configure the controller not to be a master
controller by unchecking the Master Controller Mode check box on the Master Controller
Configuration page.
Using the CLI to Verify that Access Points Join the Controller
Follow these steps to ensure that access points join the new controller.
Step 1 To configure the new controller as a master controller, enter this command:
config network master-base enable
Step 2 (Optional) Flush the ARP and MAC address tables within the network infrastructure. Ask your network
administrator for more information about this step.
Step 3 Restart the access points.
Step 4 To configure the controller not to be a master controller once all the access points have joined the new
controller, enter this command: