Step by Step guide to build a Cisco wireless infrastructure using Cisco WLC 5500, Cisco 1142 AP and Microsoft Radius server


  1. Microsoft Active Directory and DNS
  2. DHCP Server with new scope configured
  3. IP helper-address configured
  4. Microsoft Radius (IAS) Server 2003 or Microsoft Network Policy Server 2008
  5. Microsoft Enterprise root CA
  6. Cisco Wireless LAN controller (WLC) 5500
  7. Cisco AIR-LAP1142N wireless access point (AP)
  8. Separate VLAN for wireless infrastructure
  9. WLC, AP and IAS placed in same VLAN
  10. Windows 7 or Windows XP or Mac OSX/snow leopard client


1) AD and DNS working perfect.

2) DHCP Server IP:

New scope for Wireless Network

IP range: Subnet Mask:

Gateway: Exclusion:


3) WLC

IP: WLC subnet: Gateway:

Time provider:

4) IAS IP: subnet: Gateway:

5) IP ranges added in the internal networks in ISA or forefront TMG.

6)Interface 1 of WLC connected to a trunk port of Layer3 switch or core switch

7)wireless infrastructure VLAN ID/Tag 100

Add Lightweight Cisco Aironet 1142 in DHCP Server

Note: Follow these steps for newly added DHCP scope mentioned in assumptions.

1.In order to configure these options in the Windows DHCP server, open the DHCP Server Administration Tool or MMC. Right-click the DHCP root, and then choose Define Vendor Classes.

2.The DHCP Vendor Classes utility appears. Click Add.

3.A New Class configuration box appears. Enter a value for the Display Name field, for example, “Cisco Aironet c1142 AP”, and an appropriate description such as “Vendor Class identifier for Cisco Aironet c1142 AP”. Click the ASCII Section and enter the appropriate string value such as “Cisco AP c1142” (without inverted coma) for the Vendor Class Identifier. Click OK. Then, click Close on the DHCP Vendor Classes window.

4.Add an entry for the WLAN controller sub-type as a pre-defined option configured for the Vendor Class. Right-click the DHCP Server Root, and then choose Set Predefined Options.

5.Choose the newly created Vendor Option Class in the Option Class field, and then click Add.

6.The Option Type box appears. In the Name field, enter a string value, for example, Option 43. Choose IP Address as the Data Type. Check the Array check box. In the Code field, enter the sub-option code value 241 (0xf1). Enter a Description such as Wireless LAN Controller IP address. Click OK.

7.The Vendor Class and sub-option are now programmed into the DHCP server. Now, the vendor specific information must be defined for the AP DHCP scope. Choose the appropriate DHCP scope. Right-click Scope Options, and choose Configure Options.

8.Click the Advanced tab. Choose the Vendor Class you previously defined. Check the 241 Option 43 check box, and then enter each WLC management interface IP address(s) Example: Click Apply.

9.Once you complete this step, the DHCP Option 43 is configured. This DHCP option is IP address, the DHCP server sends the option 43 as well as to the LAPs. Now the DHCP option 43 (241 Cisco Wireless AP) that is made available for a newly created DHCP scope for Cisco.

10. To verify, click on the scope options in the newly created DHCP scope, you will see 241 Cisco Wireless AP or what you mentioned in Description.

Add a new VLAN in core switch(example: Cisco 4506) or L3 switch:

Note: Entire wireless infrastructure will be placed in this VLAN.

Switch#vlan database

Switch(vlan)#vlan 100

Switch(vlan)#name Wireless Network


switch#configure terminal

Switch(config-if)#interface vlan 100

Switch(config-if)#Description Wireless Network

Switch(config-if)#ip helper-address

Switch(config-if)#IP address

Switch(config-if)#no shutdown



Create a Trunk Port in Core switch (Cisco 4506) or L3 Switch

Note: This trunk will be connecting with Cisco WLC 5500 using CAT6 or Fibre optic.

Switch# configure terminal

Switch(config)#interface gigabitethernet  6/11

(6/11 means Module 6 and Port 11)

Switch(config)#switchport trunk encapsulation dot1q

Switch(config)#SwitchPort Mode trunk


Switch# wr                                              

Switch#show run

Create VLAN  in a switch (Example: Cisco 2960G)

Note: This port will be connecting with Cisco 1142 AP. Wherever you want an wireless AP, configure a port with same vlan. For this article VLAN 100. connect AP with this port after configuring the following. repeat for all the APs.                     

Switch# configure terminal


Switch(config)#interface Gigabitethernet 0/7           

Switch(config)#switchport access vlan 100            


Switch# wr             

Create AAA Server(s):

Authorization: IAS Policies (Remote Access Policies applied in IAS server for wireless 802.1x)

Authentication:Radius Server (EAP Type:PEAP,Encryption: MSCHAPv2)

Accounting:Radius server (Logs any successful and/or failed connection attempt)   

Use this link to configure Enterprise Root CA  

Install IAS in a member server. Install computer certificate in the IAS server and create new policy using this link Configure PEAP and EAP methods or follow step by step guide line in these links configure Microsoft Radius Server and Network Policy Server . It would redundant to write again.

Cisco 5500 Series Wireless Controller Installation Guide Using the Start-up Wizard

Mount Cisco 5500 in rack. Connect WLC with laptop using console port. Connect WLC with core switch or L3 switch using CAT6 cable or fibre optic if you have SFP. Now power on WLC.

Note The available options appear in brackets after each configuration parameter. The default value appears in all uppercase letters.

Note Press the hyphen key if you need to return to the previous command line. To configure the controller for basic operation using the Start-up Wizard, follow these steps:

Step 1 When prompted to terminate the Auto-Install process, enter yes. If you do not enter yes, the Auto-Install process begins after 30 seconds.

Note The Auto-Install feature downloads a configuration file from a TFTP server and then loads the configuration onto the controller automatically.

Step 2 Enter the system name, which is the name you want to assign to the controller. You can enter up to 32 ASCII characters. (Example:MS_5500)

Step 3 Enter the administrative username and password to be assigned to this controller. You can enter up to 24 ASCII characters for each. The default administrative username and password are admin and admin, respectively.(Example:username:Admin and password:cisco)

Step 4 If you want the controller’s service-port interface to obtain an IP address from a DHCP server, enter

DHCP. If you do not want to use the service port or if you want to assign a static IP address to the service-port interface, enter none.

Important! In Cisco 5500, management interface act as service interface also. No avoid any complicacy, just hit enter in this option. The service-port interface controls communications through the service port. Its IP address must be on a different subnet from the management interface. This configuration enables you to manage the controller directly or through a dedicated management network to ensure service access during network downtime.

Step 5 If you entered none in Step 4, enter the IP address and netmask for the service-port interface on the next two lines.

Step 6 Enable or disable link aggregation (LAG) by choosing yes or no. You may type No if you don’t have two or more Cisco WLC.

Step 7 Enter the IP address, netmask, default router IP address, and optional VLAN identifier (a valid VLAN identifier or 0 for an untagged VLAN) for the management interface.

Note The VLAN identifier should be set to match the switch interface configuration. Example: IP: WLC subnet: Gateway:  and VLAN tag/ID 100

Step 8 Enter the IP address of the default DHCP server that will supply IP addresses to clients, the controller’s management interface, and optionally the service-port interface.

Note The management interface is the default interface for in-band management of the controller and connectivity to enterprise services such as AAA servers.Example DHCP Server IP:

Step 9 Enter the IP address of the controller’s virtual interface, which will be used by all controller Layer 3 security and mobility managers. You should enter a fictitious, unassigned IP address, such as

Note The virtual interface is used to support mobility management, DHCP relay, and embedded Layer 3 security such as guest web authentication and VPN termination. All controllers within a mobility group must be configured with the same virtual interface IP address.

Step 10 If desired, enter the name of the mobility group/RF group to which you want the controller to belong.

Note Although the name that you enter here is assigned to both the mobility group and the RF group, these groups are not identical. Both groups define clusters of controllers, but they have different purposes. All of the controllers in an RF group are usually also in the same mobility group and vice versa. However, a mobility group facilitates scalable, system-wide mobility and controller redundancy while an RF group facilitates scalable, system-wide dynamic RF management.

Step 11 Enter the network name, or service set identifier (SSID). The initial SSID enables basic functionality of the controller and allows access points that have joined the controller to enable their radios. (Example:Mycompanywireless)

Step 12 Enter yes to allow clients to assign their own IP address or no to make clients request an IP address from a DHCP server. (Type yes in the step)

Step 13 To configure a RADIUS server now, enter yes and then enter the IP address, communication port, and secret key of the RADIUS server. Otherwise, enter no. (Type yes, IAS IP: subnet: Gateway:

Step 14 Enter the code for the country in which the controller will be used.

Note Enter help to view the list of available country codes. (Example: For Australia Country code is AU)

Step 15 Enter yes to enable or no to disable each of the 802.11b, 802.11a, 802.11g, and 802.11n lightweight access point networks. (Type yes)

Step 16 Enter yes to enable or no to disable the controller’s radio resource management (RRM) auto RF feature. (Type yes)

Note The auto RF feature enables the controller to automatically form an RF group with other controllers. The group dynamically elects a leader to optimize RRM parameter settings, such as channel and transmit power assignment, for the group.

Step 17 If you want the controller to receive its time setting from an external Network Time Protocol (NTP) server when it powers up, enter yes to configure an NTP server. Otherwise, enter no. (Type yes,Time provider: )

Step 18 If you entered no in the previous step and want to manually configure the system time on your controller now, enter yes. If you do not want to configure the system time now, enter no.

Step 19 If you entered yes in the previous step, enter the current date in MM/DD/YY format and the current time in HH:MM:SS format.

Step 20 When prompted to verify that the configuration is correct, enter yes or no. The controller saves your configuration, reboots, and prompts you to log in.

Verifying Interface Settings and Port Operation

Follow these steps to verify that your interface configurations have been set properly and the controller’s ports are operational.

Step 1 Enter show interface summary. The controller’s current interface configurations appear:

Interface Name Port VLAN Id IP Address Type AP Mgr Guest


management 1 100 Static Yes No

service-port N/A N/A Static No No

virtual N/A N/A Static No No

Step 2 Enter show port summary. The following information appears, showing the status of the controller’s distribution system ports, which serve as the data path between the controller and Cisco lightweight access points and to which the controller’s management interface is mapped.

STP Admin Physical Physical Link Link Mcast

Pr Type Stat Mode Mode Status Status Trap Appliance POE

— —

1 Normal Forw Enable Auto 1000 Full Up Enable Enable N/A

2 Normal Forw Enable Auto 1000 Full Up Enable Enable N/A

Configure Security and AAA Server in WLC 5500

1. Open IE or Firefox Type IP address of WLC in the address bar as (bypass proxy if you need to)and hit enter.

2. Click Login and provide login credentials you created in start-up wizard.

3. Click on Wireless. In the left hand pan click Authentication. You will see the IP address and port number 1812 of Radius Server.

4. In the left hand pan Click on Accounting. Click new on right hand top corner. You will be presented with a window to add Radius server. provide IP of Radius server, Shared secret and Port 1813. Apply changes.

5. Click on WLANs>Click on 1>Click on General Tab>Check Enable on Status and Check Enabled on broadcast SSID

6.Click on Security Tab>Click Layer2 Tab>Select WPA+WPA2 from Layer2  security drop-down list>Check WPA policy and TKIP or WPA2 policy and TKIP. In the same page, in Auth Key Mgmt, select 802.1x. Now click on Apply button.

7.Click on AAA Servers>Select Authentication and Accounting server from the server1 drop down list. here Authentication and Accounting server are Radius Server. Check Enabled in both Authentication and Accounting radio button. Click Apply.

8.In the left hand side top corner, click on to Monitor and scroll down to make sure you see the all APs.

Add WLC 5500 in the IAS server as a Radius Client

1. Log on to IAS server as an administrator.

2.Open Internet Authentication Service from Administrative Tools

3.Right click on Radius Clients>Click add Radius client. You will be presented with new radius client window. Type IP address of WLC 5500 and a Friendly Name such as WLC. Click Next.

4. In the this window, Select Radius Standard as Client-Vendor, Provide shared secret (must be same as WLC configuration in step 13) and repeat shared secret and click finish.

5.Close IAS console and log out.

Testing network

Log on to Windows XP or Windows 7 client as a domain users while client is connected via CAT5 or CAT6 . Make sure this domain user is a member of wireless access group and allowed to have remote access(dialin TAB of AD user property). Install computer and user certificate in that client. Now turn on wireless NIC. unplug CAT5 cable. View available wireless network. Select the SSID, you created in previous steps and double click. You will be connected.

Important! if you setup WPA and TKIP in WLC then you must setup WPA and TKIP in Client also. Similar for WPA2 and TKIP or WPA2 and AES. Both sides must match each other.

For Mac client, see my previous post in the link

Configure Group Policy for 802.1x wireless network

  1. Open the Group Policy Management Console (GPMC).
  2. Create and link a new group policy object with desired OU
  3. Right click on newly created GPO and edit
  4. Go to Computer Configuration, open Windows Settings, open Security Settings, and then select Wireless Network (IEEE 802.11) Policies.
  5. right-click Wireless Network (IEEE 802.11) Policies, and then click Create A New Policy and Type Policy name
  6. Open New Network Policy Properties >Click on preferred network Tab>To add a new profile, click Add>type the SSID that corresponds to the SSID configured on your WLC security tab.
  7. In the Wireless key network, select WPA and TKIP or whatever configured in WLC
  8. In the IEEE 802.1x tab,Set EAPOL start message to transmit per IEEE 802.1x
  9. In the EAP type select PEAP
  10. Check authenticate as computer when computer information is available and also computer authentication with user authentication from drop down box.
  11. Now press Ok, Apply and ok.

Work Around with WLC 5500 

Open IE, Type IP of WLC in the address bar (bypassing proxy), hit enter. Click on Logon. provide logon credentials, click ok.

 1 2 3 4 5 6 7 8 9 10

Accessing WLC using telnet.

Open command prompt and type telnet IP_Address


Necessary Links

Export a certificate with the private key

Import a certificate

Cisco 5500 WLC

Cisco Wireless AP

Microsoft Radius Server

Relevant Articles

WLAN Controller Failover for Lightweight Access Points Configuration Example

Wireless LAN Controller (WLC) Configuration Best Practices

How to configure Microsoft Radius Server (IAS) for Macintosh OSX 10.5, Windows 7 and windows XP Pro client

Install and configure Microsoft Active Directory Certificate Services (AD CS) using Windows Server 2008 R2

Windows Server 2008: how to configure Network Policy Server or Radius Server –Step by Step Guide

Overview of the Wi-Fi Protected Access (WPA) security update in Windows XP

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22 thoughts on “Step by Step guide to build a Cisco wireless infrastructure using Cisco WLC 5500, Cisco 1142 AP and Microsoft Radius server

  1. excellent collaboration, but the principal problem is the radius server … for example I tried to enter wireless with specifc SSDI, but it shows me a following messenger:
    “It’s imposible conect to wireless because don`t found a certificate”.

    please i need help .


  2. Very nice article, I have a weird issue though. I have the switch ports configured as the access ports, but on the management interface as well as the AP Manager Interfaces (not using a LAG). I have to untag the ports or nothing works, any ideas?


  3. Hi,
    Thanks for the excellent guide. I have a question regarding device authentication via Certificate , I want to restrict connection to the device with valid certificate. Where should I configure this restiction y ?in AD Group , IAS( Radius) or WLC and what is the role of WLC in it , just dispatcher or validater ? who actually check this certificate .
    Thanks in advance


  4. hey, the set-up i want i want is lke this. I have 2 different active directory for 2 different organisations. I nid the radius server to use realm of each domain to authenticate users depending on the domain the user belongs.
    2) I need succesful auntentications frm each domain to be put in different vlans
    3) I need failed users to be put in a guest vlan.
    Hw do i achieve ths set-up


    • if you have two different domain then you need trust relation between two domains unless you want two separate wireless vlan. you can setup as many vlans as you want if you put wlc in trunk port. you need to create separate SSID for guest vlan. you will be ok.


  5. Thnxs for rply.
    1) I need only 3vlans mapped to 3 SSID. Successful authentication in Domain A will be dynamically assigned to VLAN A, successful authentication in Domain B will be assigned to VLAN B, the failed authentication in Domain A, domain B and users without domain will be assigned to guest VLAN. ( I hve already defined the VLANS in NPS (Ms Wing Server 2008 R2 standard)

    2)I have 15 Access points, 15 SSID’s i do not have a wireless controller.
    3) I need all the access point to use the 3 SSID’s. The SSID’s are mapped to the 3 VLANS A, B & guest
    4) I need to use 802.1x authentication.

    I am vry confused as wher i will define that the successful authentication be assigned to the vlans.
    I am also confused. How the username – vlan mappings are defined.


  6. I need to use 802.1x authentication for wireless connections wthout affecting the wired devices. Do i hve to configure the switchport connected to Access point to use 802.1x or i configure the Access Points only.


  7. Hi, thanks for the answer , We are looking in IAS where we can enforce Certificate check. Currently , non corporate ( including IPHONE ) devices can also access WLAN as long as users are part of the AD Group.
    We would like to restrict to the corporate Laptops who has valid certificate and in case of missing certificate , access should be denied. . Any idea how we can do it ? Thanks in advance


  8. we have wireless network is setup vlan XX for wirless users being use. now i want radius server to authenticate users from AD. right some users have lap top mac address hard coded in APS and some mobile phone users using ifone balck berry have pre shared key configured for authentication. i want everyone to be aythenticated using AD credentials please advice Thanks


  9. Hi Raihan,
    Excelent artical really help full.

    I am planning to implement cisco wireless network in my place. idea is to have two different network one for guests and one for domain clients. I got cisco 2500 series lan controller with POE switch and 4 Cisco Aironet 1142.

    Do i need to have a radius server for domain authinticatoin or you don’t have to .

    i would appericate if you could put me in right direction.




  10. Hi Raihan,
    Excelent artical really help full.

    I am planning to implement cisco wireless network in my place. idea is to have two different network one for guests and one for domain clients. I got cisco 2500 series lan controller with POE switch and 4 Cisco Aironet 1142.

    Do i need to have a radius server for domain authinticatoin or you don’t have to .

    i would appericate if you could put me in right direction.




  11. Raihan Al-Beruni Hello
    My name is Juan Carlos, I have a 5508 wlc and RADIUS server windows 2008, follow the steps, but the server does not authenticate, I mark this bug, you can ayudarmen

    another question, works with a virtual server?


    • You can setup Cisco Wireless without WLC if you have one or two Cisco AP. WLC is for enterprise who has hundreds of AP, many VLANs, many WIFI channel and many SSID. then WLC make sense isnt it? For example University campus wide wireless for 30000 students, corporate with 50 storey building.


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