This document explains how Cisco implements web authentication and
shows how to configure a Cisco 4400 Series Wireless LAN (WLAN) Controller (WLC)
to support an Internal web authentication.
This document assumes that you already have an initial configuration on
the 4400 WLC.
The information in this document is based on these software and
A 4400 series WLC that runs version 126.96.36.199
Cisco Secure Access Control Server (ACS) version 4.2 installed on a
Microsoft® Windows 2003 Server
Cisco Aironet 1131AG Series Light Weight Access
Cisco Aironet 802.11 a/b/g CardBus Wireless Adapter that runs version
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
Web authentication is a Layer 3 security feature that causes the
controller to not allow IP traffic (except DHCP and DNS -related packets) from
a particular client until that client has correctly supplied a valid username
and password. It is a simple Authentication method without the need for a
supplicant or client utility. Web authentication is typically used by customers
who want to deploy a guest-access network. Typical deployments can include "hot
spot" locations such as T-Mobile or Starbucks.
Keep in mind that web authentication does not provide data encryption.
Web authentication is typically used as simple guest access for either a "hot
spot" or campus atmosphere where the only concern is the connectivity.
Web authentication can be performed using:
Default login window on the WLC
Modified version of the default login window on the
A customized login window that you configure on an external web
server (External web authentication)
A customized login window that you download to the controller
In this document, the Wireless LAN Controller for Internal web
authentication is configured.
This is what occurs when a user connects to a WLAN configured for web
The user opens a web browser and enters a URL, for example,
http://www.cisco.com. The client sends out a DNS request for this URL to get
the IP for the destination. The WLC bypasses the DNS request to the DNS server
and the DNS server responds back with a DNS reply, which contains the IP
address of the destination www.cisco.com. This, in turn, is forwarded to the
The client then tries to open a TCP connection with the destination
IP address. It sends out a TCP SYN packet destined to the IP address of
The WLC has rules configured for the client and hence can act as a
proxy for www.cisco.com. It sends back a TCP SYN-ACK packet to the client with
source as the IP address of www.cisco.com. The client sends back a TCP ACK
packet in order to complete the three way TCP handshake and the TCP connection
is fully established.
The client sends an HTTP GET packet destined to www.cisco.com. The
WLC intercepts this packet and sends it for redirection handling. The HTTP
application gateway prepares a HTML body and sends it back as the reply to the
HTTP GET requested by the client. This HTML makes the client go to the default
webpage URL of the WLC, for example,
The client closes the TCP connection with the IP address, for
Now the client wants to go to http://188.8.131.52/login.html. Therefore,
the client tries to open a TCP connection with the virtual IP address of the
WLC. It sends a TCP SYN packet for 184.108.40.206 to the WLC.
The WLC responds back with a TCP SYN-ACK and the client sends back a
TCP ACK to the WLC in order to complete the handshake.
The client sends a HTTP GET for /login.html destined to 220.127.116.11 in
order to request for the login page.
This request is allowed up to the Web Server of the WLC, and the
server responds back with the default login page. The client receives the login
page on the browser window where the user can go ahead and log
Here is a link to a video on the
which explains the Web Authentication process:
Authentication on Cisco Wireless LAN Controllers
This document uses this network setup:
In this document, a WLAN is configured for web authentication and
mapped to a dedicated VLAN. These are the steps involved to configure a WLAN
for web authentication:
In this section, you are presented with the information to configure
the controller for web authentication.
These are the IP addresses used in this
Complete these steps:
From the Wireless LAN controller GUI, choose
Controller from the menu at the top, choose
Interfaces from the menu on the left, and click
New on the upper right side of the window to create a new
The Interfaces > New window appears. This
example uses Interface Name vlan90 with a VLAN ID of
Click Apply in order to create the VLAN
The Interfaces > Edit window appears that asks
you to fill interface specific information.
This document uses these parameters:
Netmask—255.255.255.0 (24 bits)
Primary DHCP Server—10.77.244.204
Note: This parameter should be the IP address of your RADIUS or DHCP
server. In this example, the management address of the WLC is used as the DHCP
server because the Internal DHCP scope is configured on the WLC.
Secondary DHCP Server—0.0.0.0
Note: The example does not have a secondary DHCP server, so uses
0.0.0.0. If your configuration has a secondary DHCP server, add the server IP
address in this field.
Click Apply in order to save the
The next step is to configure the WLC for the Internal web
authentication. Internal web authentication is the default web authentication
type on WLCs. If this parameter has not been changed, no configuration is
required to enable Internal web authentication. If the web authentication
parameter was changed previously, complete these steps to configure the WLC for
Internal web authentication:
From the controller GUI, choose Security >
Web Auth > Web Login Page in order to
access the Web Login Page.
From the Web Authentication Type drop-down box, choose
Internal Web Authentication.
In the Redirect URL after login field, enter the
URL of the page to which the end user will be redirected to after successful
Note: In WLC versions 5.0 and later, the logout page for
web-authentication can also be customized. Refer to the
Login , Login failure and Logout pages per WLAN section of
Wireless LAN Controller Configuration Guide,5.2 for more
information on how to configure it.
Now that Internal web authentication has been enabled and there is a
VLAN interface dedicated for web authentication, you must provide a new
WLAN/SSID in order to support the web authentication users.
Complete these steps in order to create a new
From the WLC GUI, click WLAN in the menu at the
top, and click New on the upper right side.
Choose WLAN as the Type. Choose a profile name
and WLAN SSID for Web authentication. This example uses Guest
for both the Profile Name and WLAN SSID.
A new WLANs > Edit window appears.
Check the status box of the WLAN in order to enable the WLAN. From
the Interface menu, select the name of the VLAN interface that you created
previously. In this example, the Interface Name is
Note: Leave the default value for other parameters on this
Click the Security tab.
Complete these steps in order to configure web
Click the Layer 2 tab and set the security to
Note: You cannot configure web passthrough as Layer 3 security with
802.1x or WPA/WPA2 as Layer 2 Security for a WLAN. Refer to
LAN Controller Layer 2 Layer 3 Security Compatibility Matrix for more
information on the Wireless LAN Controller Layer 2 and Layer 3 security
Click the Layer 3 tab. Check the Web
Policy box and choose the
option, as shown here:
Click Apply in order to save the WLAN.
You are returned to the WLAN summary window. Make sure that the
Web-Auth is enabled under the Security Policies column of the WLAN table for
the SSID Guest.
There are three ways to authenticate users when you use web
authentication. Local authentication allows you to authenticate the user in the
Cisco WLC. You can also use an external RADIUS server or a LDAP server as a
backend database in order to authenticate the users.
This document provides an example configuration for all three
The user database for the guest users are stored on the WLC's local
database. Users are authenticated by the WLC against this database.
From the WLC GUI, choose
Click Local Net Users from the AAA menu on the
Click New in order to create a new
A new window displays that asks for username and password
Enter a User Name and Password in order to create a new user, then
confirm the password that you want to use.
This example creates the user named User1.
Add a description, if you choose.
This example uses Guest User1.
Click Apply in order to save the new user
Repeat steps 3-6 to add more users to the database.
This document uses a wireless ACS on Windows 2003 Server as the RADIUS
server. You can use any available RADIUS server that you currently deploy in
Note: ACS can be set up on either Windows NT or Windows 2000 Server. In
order to download ACS from Cisco.com, refer to
Software Center (Downloads) - Cisco Secure Software
(registered customers only)
You need a Cisco web account in order to download the software.
The Set Up ACS section shows you how to
configure ACS for RADIUS. You must have a fully functional network with a
Domain Name System (DNS) and a RADIUS server.
In this section, you are presented with the information to set up ACS
Set up ACS on your server and then complete these steps in order to
create a user for authentication:
When ACS asks if you want to open ACS in a browser window to
configure, click yes.
Note: After you set up ACS, you also have an icon on your
In the menu on the left, click User Setup.
This action takes you to User Setup screen as shown here:
Enter the user that you want to use for web authentication, and
After the user is created, a second window opens as shown
Ensure that the Account Disabled Box at the top is
Choose ACS Internal Database for the Password
Enter the password. Admin has an option to configure PAP/CHAP or
MD5-CHAP authentication while adding a user in the ACS internal database. PAP
is the default authentication type for web-auth users on controllers. Admin has
the flexibility to change the authentication method to chap/md5-chap using this
config custom-web radiusauth <auth method>
Complete these steps:
Click Security in the menu at the
Click RADIUS Authentication in the menu on the
Click New, and enter the IP address of your
ACS/RADIUS server. In this example, the IP address of the ACS server is
Enter the shared secret for the RADIUS server. Make sure that this
secret key is the same as the one you entered in the RADIUS server for the
Leave the Port number at the default, 1812.
Ensure that the Server Status option is
Check the Network User Enable box so that this
RADIUS Server is used for authenticating users of your wireless network.
Make sure that the Network User box is checked
and Admin Status is Enabled.
Now that the RADIUS server is configured on the WLC, you need to
configure the WLAN to use this RADIUS server for web authentication. Complete
these steps in order to configure WLAN with the RADIUS server.
Open your WLC browser and click WLANs. This
displays the list of WLANs configured on the WLC. Click the WLAN
Guest which was created for web
On the WLANs > Edit page click the
Security Menu. Click the AAA Servers tab
under Security. Then, choose the RADIUS server which is 10.77.244.196 in this
When you set up the ACS, remember to download all the current patches
and latest code. This should solve impending issues. In case you are using
RADIUS Authentication make sure that your WLC is listed as one of the AAA
Clients. Click the Network Configuration menu on the left hand
side to check this. Click the AAA client, then verify the password and the
authentication type configured. Refer to the
AAA Clients section of
Guide for Cisco Secure Access Control Server 4.2 for more information on
how to configure an AAA client.
When you choose User Setup, verify again that your users actually
exist. Click List All Users. A window as shown appears. Make
sure the user that has been created exists in the list.
This section explains how to configure a Lightweight Directory Access
Protocol (LDAP) server as a backend database, similar to a RADIUS or local user
database. An LDAP backend database allows the controller to query an LDAP
server for the credentials (username and password) of a particular user. These
credentials are then used to authenticate the user.
Complete these steps to configure LDAP using the controller GUI:
Click Security > AAA >
LDAP in order to open the LDAP Servers.
This page lists any LDAP servers that have already been configured.
If you want to delete an existing LDAP server, move your cursor
over the blue drop-down arrow for that server and choose
If you want to make sure that the controller can reach a
particular server, hover your cursor over the blue drop-down arrow for that
server and choose Ping.
Perform one of the following:
To edit an existing LDAP server, click the index number for that
server. The LDAP Servers > Edit page appears.
To add an LDAP server, click New. The LDAP
Servers > New page appears.
If you are adding a new server, choose a number from the Server
Index (Priority) drop-down box to specify the priority order of this server in
relation to any other configured LDAP servers. You can configure up to
seventeen servers. If the controller cannot reach the first server, then it
tries the second one from the list and so on.
If you are adding a new server, enter the IP address of the LDAP
server in the Server IP Address field.
If you are adding a new server, enter the LDAP server's TCP port
number in the Port Number field. The valid range is 1 to 65535, and the default
value is 389.
Check the Enable Server Status check box to
enable this LDAP server, or uncheck it to disable it. The default value is
From the Simple Bind drop-down box, choose
Anonymous or Authenticated to specify the
local authentication bind method for the LDAP server. The Anonymous method
allows anonymous access to the LDAP server, whereas the Authenticated method
requires that a username and password be entered to secure access. The default
value is Anonymous.
If you chose Authenticated in Step 7, complete these steps:
In the Bind Username field, enter a username to be used for local
authentication to the LDAP server.
In the Bind Password and Confirm Bind Password fields, enter a
password to be used for local authentication to the LDAP server.
In the User Base DN field, enter the distinguished name (DN) of the
subtree in the LDAP server that contains a list of all the users. For example,
ou=organizational unit, .ou=next organizational unit, and o=corporation.com. If
the tree containing users is the base DN, type o=corporation.com or
In the User Attribute field, enter the name of the attribute in the
user record that contains the username. You can obtain this attribute from your
In the User Object Type field, enter the value of the LDAP
objectType attribute that identifies the record as a user. Often, user records
have several values for the objectType attribute, some of which are unique to
the user and some of which are shared with other object types.
In the Server Timeout field, enter the number of seconds between
re-transmissions. The valid range is 2 to 30 seconds, and the default value is
Click Apply to commit your changes.
Click Save Configuration to save your changes.
Complete these steps if you wish to assign specific LDAP servers to
Click WLANs to open the WLANs page.
Click the ID number of the desired WLAN.
When the WLANs > Edit page appears, click the
Security > AAA Servers tabs to open the
WLANs > Edit (Security > AAA Servers) page.
From the LDAP Servers drop-down boxes, choose the LDAP server(s)
that you want to use with this WLAN. You can choose up to three LDAP servers,
which are tried in priority order.
Click Apply to commit your changes.
Click Save Configuration to save your
Once the WLC is configured, the client must be configured appropriately
for web authentication. In this section, you are presented with the information
to configure your Windows system for web authentication.
The Microsoft wireless client configuration remains mostly unchanged
for this subscriber. You only need to add the appropriate WLAN/SSID
configuration information. Complete these steps:
From the Windows Start menu, choose
Settings > Control Panel >
Network and Internet Connections.
Click the Network Connections
Right-click the LAN Connection icon and choose
Right-click the Wireless Connection icon and
Right-click the Wireless Connection icon again and
From the Wireless Network Connection Properties window, click the
Wireless Networks tab.
Under the preferred networks, area click Add in
order to configure the Web authentication SSID.
Under the Association tab, enter the Network Name (WLAN/SSID) value
that you want to use for web authentication.
Note: The Data Encryption is Wired Equivalent Privacy (WEP) by default.
Disable Data Encryption in order for web authentication to work.
Click OK at the bottom of the window in order to
save the configuration.
When you communicate with the WLAN, you see a beacon icon in the
Preferred Network box.
This shows a successful wireless connection to web authentication. The
WLC has provided your wireless Windows client with an IP
Note: If your wireless client is also a VPN end point and you have web
authentication configured as a security feature for WLAN, then the VPN tunnel
is not established until you go through the web authentication process
explained here. In order to establish a VPN tunnel, the client must first go
through the process of web authentication with success. Only then does VPN
tunneling become successful.
Note: After a successful login, if the wireless clients are idle and do not
communicate with any of the other devices, the client is de-authenticated after
an idle timeout period. The timeout period is 300 seconds by default and can be
changed using this CLI command: config network usertimeout
<seconds>. When this occurs, client entry is removed from
the controller. If the client associates again, it will move back to a
Note: If clients are active after successful login, they will get
de-authenticated and entry can still be removed from the controller after the
session timeout period configured on that WLAN (for example,1800 seconds by
default and can be changed using this CLI command: config wlan
session-timeout <WLAN ID> <seconds>). When this
occurs, client entry is removed from the controller. If the client associates
again, it will move back in a Webauth_Reqd state.
If clients are in Webauth_Reqd state, no matter if they are active or
idle, the clients will get de-authenticated after a web-auth required
timeout period (for example, 300 seconds and this time is non-user
configurable). All traffic from the client (allowed via Pre-Auth ACL) will be
disrupted. If the client associates again, it will move back to the
Complete these steps:
Open a browser window and enter any URL or IP Address. This brings
the web authentication page to the client.
If the controller is running any release earlier than 3.0, the
user has to enter https://18.104.22.168/login.html to bring up the web authentication
A security alert window displays.
Click Yes in order to
When the Login window appears, enter the username and password of
the Local Net User that you created.
If your login is successful, you see two browser windows. The
larger window indicates successful login and you can this window to browse the
internet. Use the smaller window in order to log out when your use of the guest
network is complete.
The screenshot shows a successful redirect for web
The next screenshot shows the Login Successful window, which
displays when authentication has occurred.
Cisco 4404/WiSM controllers can support 125 simultaneous Web Auth
Users logins, and scale up to 5000 web auth clients.
Cisco 5500 controllers can support 150 simultaneous Web Auth Users
If you have issues with password authentication, click Reports
and Activity on the lower left side of the ACS in order to open all
available reports. After you open the reports window, you have the option to
open RADIUS Accounting, Failed Attempts for login, Passed Authentications,
Logged-in Users, and other reports. These reports are .csv files, and you can
open the files locally on your machine. The reports help uncover issues with
authentication, such as incorrect user name and/or password. ACS also comes
with online documentation. If you are not connected to a live network and have
not defined the service port, ACS uses the IP address of your Ethernet port for
your service port. If your network is not connected, you most likely end up
with the Windows 169.254.x.x default IP address.
Note: If you type in any external URL, the WLC automatically connects you
to the internal web authentication page. If the automatic connection does not
work, you can enter the management IP address of the WLC in the URL bar in
order to troubleshoot. Look at the top of the browser for the message that says
to redirect for web authentication.
Web Authentication on a Wireless LAN Controller (WLC) for more
information on troubleshooting web authentication.
In order to configure a WLAN for IPv6 bridging, from the controller
GUI, navigate to WLANs. Then, select the desired WLAN and
choose Advanced from the WLANs >
Select the IPv6 Enable check box if you want to enable
clients that connect to this WLAN to accept IPv6 packets. Otherwise, leave the
check box unselected, which is the default value. If you disable (or uncheck)
the IPv6 check box, IPv6 will only be allowed after authentication. Enabling
IPv6 means that the controller can pass IPv6 traffic without client
For more detailed information on IPv6 bridging and the
guidelines for using this feature, refer to the
IPv6 Bridging section of
Wireless LAN Controller Configuration Guide, Release 7.0.