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Cisco 4400 Series Wireless LAN Controllers

AutoInstall Feature of WLC with IOS DHCP Server Configuration Example

Document ID: 111452

Updated: Dec 15, 2009

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Introduction

This document provides information on how the AutoInstall feature works on a Wireless LAN Controller (WLC) that uses Cisco IOS® Router as the DHCP server.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

  • Configuring the WLC for basic operation

  • Basic knowledge of Lightweight Access Point Protocol (LWAPP)

Components Used

The information in this document is based on these hardware and software versions:

  • 4400 series WLC that runs version 6.0

  • 2800 series router that runs software version 12.4(11)

  • Any TFTP server that can upload files greater than 32 MB

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

AutoInstall Feature of WLC

The AutoInstall feature is implemented starting with WLC software version 5.0 and later. When you boot up a controller that does not have a configuration, the AutoInstall feature can download a configuration file from a TFTP server and then load the configuration to the controller automatically. Create a configuration file from a controller that is already on the network (or through a WCS filter) and place that configuration file on a TFTP server. Configure a DHCP server such that it povides IP address, TFTP server, hostname, etc., to the WLC. The AutoInstall feature can obtain the configuration file for the new controller automatically. When the controller boots, the AutoInstall process starts with this prompt and stays for 30 seconds:

Would you like to terminate autoinstall? [yes]:

If you hit Enter or type 'yes', then AutoInstall ends. Or else after the 30-second abort timeout expires, AutoInstall starts the DHCP client. You can abort the AutoInstall task even after this 30 second timeout if you enter Yes at the prompt. However, AutoInstall cannot be aborted if the TFTP task has locked the flash and is in the process of downloading and installing a valid configuration file.

AutoInstall uses these interfaces:

  • 4400 series controllers

    • eth0—Service port (untagged)

    • dtl0—Gigabit port 1 through the NPU (untagged)

  • 2100 series controllers

    • dtl0—FastEthernet port 1 (untagged)

For the AutoInstall feature to work, the DHCP server should be configured to provide one of these options to the WLC, along with the IP address and TFTP server information.

  • The filename that is provided by the DHCP Boot File Name option

  • The filename that is provided by the DHCP File field

  • host name-confg

  • host name.cfg

  • base MAC address-confg (for example, 0011.2233.4455-confg)

  • serial number-confg

  • ciscowlc-confg

  • ciscowlc.cfg

AutoInstall runs through this list until it finds a configuration file on the TFTP server. AutoInstall performs three full download iterations on each interface that obtains a DHCP IP address. For example, if a 4400 series controller obtains DHCP IP addresses on both eth0 and dtl0, each interface tries to download a configuration. The first configuration file that is downloaded and installed successfully triggers a reboot of the controller. For more information on the AutoInstall feature, refer to the WLC Configuration Guide 6.0.

Note: In this example, the DHCP Boot File Name option is used.

Note: The downloaded configuration file can be a complete configuration, or it can be a minimal configuration that provides enough information for the controller to be managed by the WCS. Full configuration can then be deployed directly from the WCS. WCS release 5.0 or later provides AutoInstall capabilities for controllers. A WCS administrator can create a filter that includes the host name, the MAC address, or the serial number of the controller and associate a group of templates (a configuration group) to this filter rule. The WCS pushes the initial configuration to the controller when the controller boots up initially. After the controller is discovered, the WCS pushes the templates that are defined in the configuration group.

Note: The Cisco WiSM controllers do not support the AutoInstall feature.

Configuring DHCP Server

In this document's example, Cisco IOS router is used as the DHCP server. These IP addresses are used:

  • 10.77.244.196 - TFTP Server

  • 10.77.244.220 - DHCP Server

It is assumed that the IOS router is already configured and active on the network. Here, only the DHCP configuration required for this document is shown:

2800-ISR-TSWEB#show run
Building configuration...

Current configuration : 2029 bytes


ip dhcp excluded-address 10.77.244.193 10.77.244.196
ip dhcp excluded-address 10.77.244.200 10.77.244.206
ip dhcp excluded-address 10.77.244.210 10.77.244.220

!--- (Exclude the addresses that are already assigned in the Subnet)

!
ip dhcp pool pool1 

!--- Configures the IP Pool to be assigned to this WLC.

   network 10.77.244.192 255.255.255.224
   bootfile WLC-4400.cfg 

!--- (Name of the bootfile that is provided to the - WLC)

   default-router 10.77.244.193
   option 150 ip 10.77.244.196 

!--- (This option is meant to assign TFTP Server to the WLC)
.
!
!
interface FastEthernet0/0.1
 encapsulation dot1Q 1 native
 i

Sample Output of AutoInstall Implementation on WLC

This is an example of an AutoInstall process from start to finish:

(Cisco Controller) >reset system


System will now restart!


Would you like to terminate autoinstall? [yes]:
AUTO-INSTALL: starting now...
rc = 0

AUTO-INSTALL: interface 'service-port' - setting DHCP file ==> 'WLC-4400.cfg'

AUTO-INSTALL: interface 'service-port' - setting DHCP TFTP Server IP ==> 10.77.244.196

AUTO-INSTALL: interface 'service-port' - setting DHCP siaddr ==> 10.77.244.220

AUTO-INSTALL: interface 'service-port' - setting DHCP Host Name ==> ' '

AUTO-INSTALL: interface 'service-port' - setting DHCP yiaddr ==> 10.77.244.197

AUTO-INSTALL: interface 'service-port' - setting DHCP Netmask ==> 255.255.255.224

AUTO-INSTALL: interface 'service-port' - setting DHCP Gateway ==> 10.77.244.193

AUTO-INSTALL: interface 'service-port' registered

AUTO-INSTALL: iteration 1 -- interface 'service-port'

AUTO-INSTALL: hostname ' '

AUTO-INSTALL: TFTP server 10.77.244.196 (from DHCP Option 150)

AUTO-INSTALL: attempting download of 'WLC-4400.cfg'

AUTO-INSTALL: TFTP status - 'TFTP Config transfer starting.'

AUTO-INSTALL: TFTP status - 'TFTP receive complete... updating configuration.'

AUTO-INSTALL: TFTP status - 'Warning! No AP will come up unless the time is set.
 
'

AUTO-INSTALL: TFTP status - 'TFTP receive complete... storing in flash.'

AUTO-INSTALL: TFTP status - 'System being reset.'


Resetting system ...

In this example you can see that the WLC is assigned an IP address (10.77.244.196) on it's service port, TFTP Server information and the boot file name - WLC-4400.cfg necessary to be downloaded from the TFTP server. Once the configuration file is obtained from the TFTP server, the WLC automatically restarts with the configuration file obtained.

Related Information

Updated: Dec 15, 2009
Document ID: 111452