User's Manual

Deployment Notes

Using a DHCP Server in a Layer 3 Mesh

Network

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.

Configuring DHCP Option 43

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:

http://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a0080871

4fe.shtml

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

following URL:

http://www.cisco.com/en/US/docs/wireless/technology/controller/deployment/guide/dep.html#wp106

8287

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

Note 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 c1532.

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