Cisco Cisco Aironet 1530i Outdoor Access Point Guida All'Installazione

To use a DHCP server in a Layer 3 mesh network, you must configure DHCP option 43 on the DHCP 
server. After the controller is restarted, the access point receives IP addresses from the DHCP server.

You can use DHCP Option 43 to provide a list of controller IP addresses to the access points, enabling 
each access point to find and join a controller. This section contains a DHCP Option 43 configuration 
example on a Microsoft Windows 2003 Enterprise DHCP server for use with Cisco Aironet 
lightweight access points. 

Additional information about Microsoft DHCP Option 43 is available on Cisco.com at the following 
URL:

DHCP Option 43 server implementation information for Cisco IOS is available at cisco.com at the 
following URL:

In DHCP Option 43, you should use the IP address of the controller management interface.

DHCP Option 43 is limited to one access point type per DHCP pool. You must configure a 
separate DHCP pool for each access point type.

Cisco 1532 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 DHCP Vendor Class Identifier (VCI) string 
(DHCP Option 60) of the access point. The VCI string for the Cisco 1532 access point is 
Cisco AP c1530.

The format of the TLV block for the 1532 access point is listed below: 

Type: 0xf1 (decimal 241) 

Length: Number of controller IP addresses * 4 

Value: List of WLC management interfaces