Cisco Aironet 1815w Getting Started Manual page 39

Configuring DHCP Option 43
You can use DHCP Option 43 to provide a list of controller IP addresses to the access points, enabling
them to find and join a controller.
The following is a DHCP Option 43 configuration example on a Windows 2003 Enterprise DHCP
server for use with Cisco Aironet lightweight access points. For other DHCP server implementations,
consult product documentation for configuring DHCP Option 43. In 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
Note
separate DHCP pool for each access point type.
The Cisco Aironet 1815w access point uses 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 43). The VCI string for the Cisco Aironet 1815w access
point is:
Cisco AP c1810
The format of the TLV block is listed below:
• Type: 0xf1 (decimal 241)
• Length: Number of controller IP addresses * 4
• Value: List of WLC management interfaces
To configure DHCP Option 43 in the embedded Cisco DHCP server, follow these steps:
Enter configuration mode at the CLI.
Step 1
Create the DHCP pool, including the necessary parameters such as default router and name
Step 2
server. A DHCP scope example is as follows:
ip dhcp pool <pool name>
network <IP Network> <Netmask>
default-router <Default router>
dns-server <DNS Server>
Where:
<pool name> is the name of the DHCP pool, such as AP1815W