Catalyst 4500 Series Switch Software Configuration Guide, IOS XE 3.9.xE and IOS 15.2(5)Ex

Restrictions for Wired Guest Access

• Wired guest access does not work on Supervisor Engine 8-E, in multiple-host mode or in multi- authentication mode.
• Wired guest access works on Supervisor Engine 8-E in wireless mode only.
• Tunneling of wired clients is not supported when the client is attached to a port at the Cisco Next Generation Wiring Closet (NGWC) device that is configured for open mode.
• Tunneling of wired clients is not supported after successful web authentication at the NGWC device because automated IP address reassignment is not supported after web-authentication.
• The NGWC device supports network access only via the tunnel based on the web authentication that occurs at the controller.
• The Network Advertisement and Selection Protocol (NASP) is not supported for wired clients.
• High availability is not supported for wireless sessions. If the wireless controller fails while providing tunneled guest access for a wired client, the state is not automatically recovered.
• Inactivity aging is not enforced for a wired client that is provisioned to the wireless controller; for example, within a RADIUS Access-Accept request that is received after web authentication is performed at the controller.

Wired Guest Access Overview

Enterprise networks that support both wired and wireless access need to provide guest services that are consistent across the two access media, from a perspective of both client experience and manageability. For wireless networks, guest traffic from a mobility anchor device is directed typically through a Control And Provisioning of Wireless Access Points (CAPWAP) tunnel to an array of controllers in the demilitarized zone (DMZ), where either web-authenticated access or open access is provided. Wired guest traffic can also be backhauled to the DMZ using more traditional tunneling mechanisms like Generic Routing Encapsulation (GRE). The Cisco Next Generation Wiring Closet (NGWC) platforms, with converged wired and wireless access, can extend CAPWAP tunneling to wired guests also, allowing for very similar handling at the controller platform (in the DMZ) and reducing the provisioning overhead.

However, security remains an issue because it is not possible to determine, prior to authentication, whether a wired client is a guest or requires access to the corporate network. Consequently, the decision to tunnel a wired client’s traffic to the DMZ cannot be made with the certain knowledge that the client is a guest.

Due to the lack of network selection for wired clients, open mode cannot be supported with guest tunneling. Open mode is when an IP address is allocated as soon as a client connects to the access switch. Once the client is connected via a tunnel, it must be reassigned an IP address from a subnet provisioned at the DMZ, before web authentication can be attempted.

Converged Guest Access Solution

In the preceding figure, the Cisco Next Generation Wiring Closet (NGWC) device forms the attachment point for both wired and wireless sessions and provides Layer 2 authentication, where applicable. Wired session guests on a mobility agent (a foreign device) are directed through a Control And Provisioning of Wireless Access Points (CAPWAP) tunnel to the wireless controller (the anchor device) in the demilitarized zone (DMZ). The wired session guests are provided open or web-authenticated access from the wireless controller. This approach simplifies the management of guest access because only one network device is provisioned to manage HTTP traffic and serve web pages.

Tunneling wired guest traffic to the DMZ allows the same controller platform to provide web-authenticated and open access to wired guests also, further simplifying the management of guest access and ensuring a consistent experience for end users. To activate the CAPWAP tunnel, matching guest LAN profiles must be configured on foreign and anchor devices.

Authentication, authorization, and accounting (AAA) services are required at the access layer for Layer 2 authentication and, optionally, to direct the device to open a tunnel for a wired client. A DMZ uses AAA for client guest authentication. The Mobility Controller/Mobility Tunnel Endpoint (MC/MTE) allows the CAPWAP tunnel to the DMZ to be load-balanced across an array of wireless controllers.

CAPWAP Tunneling

In an enterprise Edge (eEdge) implementation of wired guest access, Control And Provisioning of Wireless Access Points (CAPWAP) tunneling is implemented as an Enterprise Policy Manager (EPM) plug-in.

When a tunnel is specified within a user profile or a service template, the EPM invokes the CAPWAP tunnel. The EPM requests that the Wireless Controller Module (WCM) establish a CAPWAP tunnel for the session on which the EPM is installed. If the WCM returns an error or indicates unsolicited tunnel termination at any subsequent point, the CAPWAP tunnel notifies the EPM of failure. The failure results in an authorization-failure event at the session manager, and a control policy rule can be specified to determine the failure handling.

The Session Manager is responsible for creating and managing wired sessions in the eEdge framework. It assigns an audit-session-id at session creation and stores client identity data in a session entry in the database. It also manages the authentication of connecting endpoints where authentication is specified under a control policy.

Based on requests, the WCM is responsible for the CAPWAP tunneling of wired clients at an NGWC switch. The WCM also provides identical handling of tunneled wireless and wired guest sessions at the controller.

Note A new tunnel is established only if it does not exist between the access switch and the relevant controller. If a tunnel exists, a client is added to it.

Note The Vendor-specific attribute (VSA) for activating CAPWAP tunneling using user profiles is “subscriber:capwap-tunnel-profile-name= name”.

Configuring Guest LAN

To configure a guest LAN, follow these steps:

Configuring a CAPWAP Tunnel in a Service Template

Perform the following task to configure a Control And Provisioning of Wireless Access Points (CAPWAP) tunnel in a service template and to activate a tunnel service when Layer 2 authentication failure occurs.

Configuring CAPWAP Forwarding

Perform the following task to configure a specific VLAN for CAPWAP forwarding. Once configured, this VLAN can be used only for CAPWAP forwarding.

Example: Configuring a CAPWAP Tunnel in a Service Template

The following example shows how to configure a CAPWAP tunnel in a service template to enable wired guest access.

Example: Configuring the Mobility Agent

The following example shows how to configure interface ports on the mobility agent (anchor).

Wired-guest-access ports initially terminate on a Layer 2 access switch or switch port configured with VLAN interfaces for wired-guest-access traffic. The wired guest traffic is then trunked from the access switch to a controller. This controller is configured with an interface that is mapped to a wired-guest-access VLAN on the access switch.

Example: Configuring the Mobility Controller

The following example shows how to configure the interface ports and wireless mobility on the mobility controller to enable wired guest access.

Example: Configuring the Guest Controller

The following example shows how to configure interface ports on the guest controller (anchor) and how to set up DHCP snooping.

The guest (local WLAN) controller anchors the client onto a demilitarized zone (DMZ) anchor WLAN controller that is configured for wired and wireless guest access. After a successful handoff of the client to the DMZ anchor controller, the DHCP IP address assignment, client authentication, and so on are handled in the DMZ Cisco Wireless LAN Controller (WLC). After WLC completes the authentication, the client is allowed to send and receive traffic.

Example: Configuring CAPWAP Forwarding