Getting Started Guide
Table Of Contents
- Cisco Aironet 1840 Series Access Points
- 1 About this Guide
- 2 About the Access Point
- 3 Safety Instructions
- 4 Unpacking
- 5 AP Views, Ports, and Connectors
- 6 Preparing the AP for Installation
- 7 Installation Overview
- 8 Performing a Pre-Installation Configuration
- 9 Mounting the Access Point
- 10 Powering the Access Point
- 11 Configuring and Deploying the Access Point
- 12 Checking the Access Point LEDs
- 13 Miscellaneous Usage and Configuration Guidelines
- 14 Related Documentation
- 15 Declarations of Conformity and Regulatory Information
- Manufacturers Federal Communication Commission Declaration of Conformity Statement
- VCCI Statement for Japan
- Guidelines for Operating Cisco Aironet Access Points in Japan
- Statement 371—Power Cable and AC Adapter
- Industry Canada
- Canadian Compliance Statement
- European Community, Switzerland, Norway, Iceland, and Liechtenstein
- Declaration of Conformity for RF Exposure
- Generic Discussion on RF Exposure
- This Device Meets International Guidelines for Exposure to Radio Waves
- This Device Meets FCC Guidelines for Exposure to Radio Waves
- This Device Meets the Industry Canada Guidelines for Exposure to Radio Waves
- Cet appareil est conforme aux directives internationales en matière d'exposition aux fréquences radioélectriques
- Additional Information on RF Exposure
- Administrative Rules for Cisco Aironet Access Points in Taiwan
- Operation of Cisco Aironet Access Points in Brazil
- Declaration of Conformity Statements
- Communications, Services, and Additional Information
- Cisco Bug Search Tool
18
Cisco Aironet 1840 Series Access Points
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.
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.
The 1840 series 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 DHCP Vendor Class Identifier (VCI) string (DHCP Option 43).
The VCI string for the 1840 series access point is:
Cisco AP c1840
The format of the TLV block is listed below:
Type—0xf1 (decimal 241)
Length—Number of controller IP addresses * 4
Value—IP addresses of the WLC management interfaces listed sequentially in hex
To configure DHCP Option 43 in the embedded Cisco IOS DHCP server, follow these steps:
Step 1 Enter configuration mode at the Cisco IOS CLI.
Step 2 Create the DHCP pool, including the necessary parameters such as default router and name 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 AP1840
<IP Network> is the network IP address where the controller resides, such as 10.0.15.1
<Netmask> is the subnet mask, such as 255.255.255.0
<Default router> is the IP address of the default router, such as 10.0.0.1
<DNS Server> is the IP address of the DNS server, such as 10.0.10.2
Step 3 Add the option 43 line using the following syntax:
option 43 hex <hex string>
The hex string is assembled by concatenating the TLV values shown below:
Type + Length + Value
For example, suppose that there are two controllers with management interface IP addresses, 10.126.126.2 and
10.127.127.2. The type is f1(hex). The length is 2 * 4 = 8 = 08 (hex). The IP addresses translate to 0a7e7e02 and
0a7f7f02. Assembling the string then yields f1080a7e7e020a7f7f02. The resulting Cisco IOS command added to the
DHCP scope is option 43 hex f1080a7e7e020a7f7f02.