Cisco Wireless LAN Controller Configuration Guide, Release 7.0
Chapter 1 - Overview
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Overview

Table Of Contents

Overview

Cisco Unified Wireless Network Solution Overview

Single-Controller Deployments

Multiple-Controller Deployments

Operating System Software

Operating System Security

Cisco WLAN Solution Wired Security

Layer 2 and Layer 3 Operation

Operational Requirements

Configuration Requirements

Cisco Wireless LAN Controllers

Client Location

Controller Platforms

Cisco 2100 Series Controller

Features Not Supported

Cisco 4400 Series Controllers

Cisco 5500 Series Controllers

Features Not Supported

Catalyst 6500 Series Switch Wireless Services Module

Cisco 7600 Series Router Wireless Services Module

Cisco 28/37/38xx Series Integrated Services Router

Features Not Supported

Catalyst 3750G Integrated Wireless LAN Controller Switch

Cisco UWN Solution Wired Connections

Cisco UWN Solution WLANs

File Transfers

Power Over Ethernet

Cisco Wireless LAN Controller Memory

Cisco Wireless LAN Controller Failover Protection

Network Connections to Cisco Wireless LAN Controllers

Cisco 2100 Series Wireless LAN Controllers

Cisco 4400 Series Wireless LAN Controllers

Cisco 5500 Series Wireless LAN Controllers


Overview


This chapter describes the controller components and features. It contains these sections:

Cisco Unified Wireless Network Solution Overview

Operating System Software

Operating System Security

Layer 2 and Layer 3 Operation

Cisco Wireless LAN Controllers

Controller Platforms

Cisco UWN Solution Wired Connections

Cisco UWN Solution WLANs

File Transfers

Power Over Ethernet

Cisco Wireless LAN Controller Memory

Cisco Wireless LAN Controller Failover Protection

Network Connections to Cisco Wireless LAN Controllers

Cisco Unified Wireless Network Solution Overview

The Cisco Unified Wireless Network (Cisco UWN) solution is designed to provide 802.11 wireless networking solutions for enterprises and service providers. The Cisco UWN solution simplifies deploying and managing large-scale wireless LANs and enables a unique best-in-class security infrastructure. The operating system manages all data client, communications, and system administration functions, performs radio resource management (RRM) functions, manages system-wide mobility policies using the operating system security solution, and coordinates all security functions using the operating system security framework.

The Cisco UWN solution consists of Cisco wireless LAN controllers and their associated lightweight access points controlled by the operating system, all concurrently managed by any or all of the operating system user interfaces:

An HTTP and/or HTTPS full-featured Web User Interface hosted by Cisco wireless LAN controllers can be used to configure and monitor individual controllers. See Chapter 2 "Getting Started."

A full-featured command-line interface (CLI) can be used to configure and monitor individual Cisco wireless LAN controllers. See Chapter 2 "Getting Started."

The Cisco Wireless Control System (WCS), which you use to configure and monitor one or more Cisco wireless LAN controllers and associated access points. WCS has tools to facilitate large-system monitoring and control. WCS runs on Windows 2000, Windows 2003, and Red Hat Enterprise Linux ES servers.


Note WCS software release 7.0 must be used with controllers that run controller software release 7.0. Do not attempt to use older versions of the WCS software with controllers that run controller software release 7.0.


An industry-standard SNMP V1, V2c, and V3 interface can be used with any SNMP-compliant third-party network management system.

The Cisco UWN solution supports client data services, client monitoring and control, and all rogue access point detection, monitoring, and containment functions. It uses lightweight access points, Cisco wireless LAN controllers, and the optional Cisco WCS to provide wireless services to enterprises and service providers.


Note Unless otherwise noted in this publication, all of the Cisco wireless LAN controllers are referred to as controllers, and all of the Cisco lightweight access points are referred to as access points.


Figure 1-1 shows the Cisco wireless LAN controller components, which can be simultaneously deployed across multiple floors and buildings.

Figure 1-1 Cisco UWN Solution Components

Single-Controller Deployments

A standalone controller can support lightweight access points across multiple floors and buildings simultaneously and support the following features:

Autodetecting and autoconfiguring lightweight access points as they are added to the network.

Full control of lightweight access points.

Lightweight access points connect to controllers through the network. The network equipment may or may not provide Power over Ethernet (PoE) to the access points.

Some controllers use redundant Gigabit Ethernet connections to bypass single network failures.


Note Some controllers can connect through multiple physical ports to multiple subnets in the network. This feature can be helpful when you want to confine multiple VLANs to separate subnets.


Figure 1-2 shows a typical single-controller deployment.

Figure 1-2 Single-Controller Deployment

Multiple-Controller Deployments

Each controller can support lightweight access points across multiple floors and buildings simultaneously. However, full functionality of the Cisco wireless LAN solution occurs when it includes multiple controllers. A multiple-controller system has the following additional features:

Autodetecting and autoconfiguring RF parameters as the controllers are added to the network.

Same-subnet (Layer 2) roaming and inter-subnet (Layer 3) roaming.

Automatic access point failover to any redundant controller with a reduced access point load (see the Cisco Wireless LAN Controller Failover Protection).

Figure 1-3 shows a typical multiple-controller deployment. The figure also shows an optional dedicated management network and the three physical connection types between the network and the controllers.

Figure 1-3 Typical Multiple-Controller Deployment

Operating System Software

The operating system software controls controllers and lightweight access points. It includes full operating system security and radio resource management (RRM) features.

Operating System Security

Operating system security bundles Layer 1, Layer 2, and Layer 3 security components into a simple, Cisco WLAN solution-wide policy manager that creates independent security policies for each of up to 16 wireless LANs. See the Cisco UWN Solution WLANs.

The 802.11 Static WEP weaknesses can be overcome using the following robust industry-standard security solutions:

802.1X dynamic keys with extensible authentication protocol (EAP).

Wi-Fi protected access (WPA) dynamic keys. The Cisco WLAN solution WPA implementation includes:

Temporal key integrity protocol (TKIP) and message integrity code checksum dynamic keys

WEP keys, with or without a preshared key p assphrase

RSN with or without a preshared key

Optional MAC filtering

The WEP problem can be further solved using the following industry-standard Layer 3 security solutions:

Passthrough VPNs

Local and RADIUS MAC address filtering

Local and RADIUS user/password authentication

Manual and automated disabling to block access to network services. In manual disabling, you block access using client MAC addresses. In automated disabling, which is always active, the operating system software automatically blocks access to network services for a user-defined period of time when a client fails to authenticate for a fixed number of consecutive attempts. This feature can be used to deter brute-force login attacks.

These and other security features use industry-standard authorization and authentication methods to ensure the highest possible security for your business-critical wireless LAN traffic.

Cisco WLAN Solution Wired Security

Each controller and lightweight access point is manufactured with a unique, signed X.509 certificate. These signed certificates are used to verify downloaded code before it is loaded, ensuring that hackers do not download malicious code into any controller or lightweight access point.

The controllers and lightweight access points also use the signed certificates to verify the downloaded code before it is loaded, ensuring that hackers do not download malicious code into any Cisco wireless controller or lightweight access point.

Layer 2 and Layer 3 Operation

Lightweight Access Point Protocol (LWAPP) communications between the controller and lightweight access points can be conducted at Layer 2 or Layer 3. Control and Provisioning of Wireless Access Points protocol (CAPWAP) communications between the controller and lightweight access points are conducted at Layer 3. Layer 2 mode does not support CAPWAP.


Note Controller software release 5.2 or later releases support only Layer 3 CAPWAP mode, controller software releases 5.0 and 5.1 support only Layer 3 LWAPP mode, and controller software releases prior to 5.0 support Layer 2 or Layer 3 LWAPP mode.



Note The IPv4 network layer protocol is supported for transport through a CAPWAP or LWAPP controller system. IPv6 (for clients only) and Appletalk are also supported but only on Cisco 5500 Series Controllers, Cisco 4400 Series Controllers, and the Cisco WiSM. Other Layer 3 protocols (such as IPX, DECnet Phase IV, OSI CLNP, and so on) and Layer 2 (bridged) protocols (such as LAT and NetBeui) are not supported.


Operational Requirements

The requirement for Layer 3 LWAPP communications is that the controller and lightweight access points can be connected through Layer 2 devices on the same subnet or connected through Layer 3 devices across subnets. Another requirement is that the IP addresses of access points should be either statically assigned or dynamically assigned through an external DHCP server.

The requirement for Layer 3 CAPWAP communications across subnets is that the controller and lightweight access points are connected through Layer 3 devices. Another requirement is that the IP addresses of access points should be either statically assigned or dynamically assigned through an external DHCP server.

Configuration Requirements

When you are operating the Cisco wireless LAN solution in Layer 2 mode, you must configure a management interface to control your Layer 2 communications.

When you are operating the Cisco wireless LAN solution in Layer 3 mode, you must configure an AP-manager interface to control lightweight access points and a management interface as configured for Layer 2 mode.

Cisco Wireless LAN Controllers

When you are adding lightweight access points to a multiple-controller deployment network, it is convenient to have all lightweight access points associate with one master controller on the same subnet. That way, the you do not have to log into multiple controllers to find out which controller newly-added lightweight access points associated with.

One controller in each subnet can be assigned as the master controller while adding lightweight access points. As long as a master controller is active on the same subnet, all new access points without a primary, secondary, and tertiary controller assigned automatically attempt to associate with the master controller. This process is described in the Cisco Wireless LAN Controller Failover Protection.

You can monitor the master controller using the WCS Web User Interface and watch as access points associate with the master controller. You can then verify the access point configuration and assign a primary, secondary, and tertiary controller to the access point, and reboot the access point so it reassociates with its primary, secondary, or tertiary controller.


Note Lightweight access points without a primary, secondary, and tertiary controller assigned always search for a master controller first upon reboot. After adding lightweight access points through the master controller, you should assign primary, secondary, and tertiary controllers to each access point. We recommend that you disable the master setting on all controllers after initial configuration.


Client Location

When you use Cisco WCS in your Cisco wireless LAN solution, controllers periodically determine the client, rogue access point, rogue access point client, radio frequency ID (RFID) tag location and store the locations in the Cisco WCS database. For more information on location solutions, see these documents:

Cisco Wireless Control System Configuration Guide:

http://www.cisco.com/en/US/products/ps6305/products_installation_and_configuration_guides_list.html

Cisco Location Appliance Configuration Guide:

http://www.cisco.com/en/US/products/ps6386/products_installation_and_configuration_guides_list.html

Cisco 3300 Series Mobility Services Engine Configuration Guide:

http://www.cisco.com/en/US/products/ps9742/products_installation_and_configuration_guides_list.html

Controller Platforms

Controllers are enterprise-class high-performance wireless switching platforms that support 802.11a/n and 802.11b/g/n protocols. They operate under control of the operating system, which includes the radio resource management (RRM), creating a Cisco UWN solution that can automatically adjust to real-time changes in the 802.11 RF environment. Controllers are built around high-performance network and security hardware, resulting in highly reliable 802.11 enterprise networks with unparalleled security.

The following controllers are supported for use with software release 7.0:

Cisco 2100 Series Controller

Cisco 4400 Series Controller

Cisco 5500 Series Controller

Catalyst 6500 series switch Wireless Services Module (WiSM)

Cisco 7600 Series Router Wireless Services Module (WiSM)

Cisco 28/37/38xx Series Integrated Services Router with Controller Network Module

Catalyst 3750G Integrated Wireless LAN Controller Switch

The first three controllers are standalone platforms. The remaining four controllers are integrated into Cisco switch and router products.

Cisco 2100 Series Controller

The Cisco 2100 Series Wireless LAN Controllers work with Cisco lightweight access points and the Cisco Wireless Control System (WCS) to provide system-wide wireless LAN functions. Each controller controls up to 6, 12, or 25 lightweight access points for multiple-controller architectures that are typical of enterprise branch deployments. It may also be used for single controller deployments for small and medium-sized environments.


Caution Do not connect a Power-over-Ethernet (PoE) cable to the controller's console port. Doing so may damage the controller.


Note Wait at least 20 seconds before reconnecting an access point to the controller. Otherwise, the controller may fail to detect the device.


Features Not Supported

This hardware feature is not supported on Cisco 2100 Series Controllers:

Service port (separate out-of-band management 10/100-Mbps Ethernet interface)

These software features are not supported on Cisco 2100 Series Controllers:

VPN termination (such as IPsec and L2TP)

VPN passthrough option


Note You can replicate this functionality on a Cisco 2100 Series Controller by creating an open WLAN using an ACL.


Termination of guest controller tunnels (origination of guest controller tunnels is supported)

External web authentication web server list

Spanning Tree Protocol (STP)

Port mirroring

AppleTalk

QoS per-user bandwidth contracts

IPv6 pass-through

Link aggregation (LAG)

Multicast-unicast mode

Cisco 4400 Series Controllers

The Cisco 4400 Series Wireless LAN Controller is available in two models: 4402 and 4404. The 4402 supports up to 50 lightweight access points while the 4404 supports up to 100, making it ideal for large enterprises and high-density applications.

The Cisco 4400 Series Controller can be equipped with one or two power supplies. When the controller is equipped with two power supplies, the power supplies are redundant, and either power supply can continue to power the controller if the other power supply fails.

Cisco 5500 Series Controllers

The Cisco 5500 Series Wireless LAN Controller is currently available in one model: 5508. The 5508 controller supports up to 500 lightweight access points and 7000 wireless clients (or 5000 wireless clients and 2500 RFID tags when using the client location feature), making it ideal for large enterprises and high-density applications.

The Cisco 5500 Series Controller can be equipped with one or two power supplies. When the controller is equipped with two power supplies, the power supplies are redundant, and either power supply can continue to power the controller if the other power supply fails.

Features Not Supported

These software features are not supported on Cisco 5500 Series Controllers:

Static AP-manager interface


Note For Cisco 5500 Series Controllers, you are not required to configure an AP-manager interface. The management interface acts like an AP-manager interface by default, and the access points can join on this interface.


Asymmetric mobility tunneling

Spanning Tree Protocol (STP)

Port mirroring

Layer 2 access control list (ACL) support

VPN termination (such as IPsec and L2TP)

VPN passthrough option


Note You can replicate this functionality on a Cisco 5500 Series Controller by creating an open WLAN using an ACL.


Configuration of 802.3 bridging, AppleTalk, and Point-to-Point Protocol over Ethernet (PPPoE)


Note The Cisco 5500 Series Controllers bridge these packets by default. If desired, you can use ACLs to block the bridging of these protocols.


Catalyst 6500 Series Switch Wireless Services Module

The Catalyst 6500 series switch Wireless Services Module (WiSM) is an integrated Catalyst 6500 series switch and two Cisco 4404 controllers that supports up to 300 lightweight access points. The switch has eight internal Gigabit Ethernet ports that connect the switch and the controller. The switch and the internal controller run separate software versions, which must be upgraded separately.


Note Without any other service module installed, the Catalyst 6509 switch chassis can support up to seven Cisco WiSMs, and the Catalyst 6506 with a Supervisor 720 can support up to four Cisco WiSMs. If one or more service modules are installed, the chassis can support up to a maximum of four service modules (WiSMs included). Redundant supervisors cannot be used with these maximum configurations.



Note The Cisco WiSM controllers do not support port mirroring.


See the following documents for additional information:

Catalyst 6500 Series Switch Installation Guide

Catalyst 6500 Series Switch Wireless Services Module Installation and Configuration Note

Release Notes for Catalyst 6500 Series Switch Wireless LAN Services Module

Configuring a Cisco Wireless Services Module and Wireless Control System

Catalyst 6500 Series Switch and Cisco 7600 Series Router Wireless Services Module Installation and Verification Note

You can find these documents at these URLs:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html

http://www.cisco.com/en/US/docs/wireless/technology/wism/technical/reference/appnote.html

http://www.cisco.com/en/US/docs/wireless/technology/wism/installation/note/78_17121.html

Cisco 7600 Series Router Wireless Services Module

The Cisco 7600 series Router Wireless Services Module (WiSM) is an integrated Cisco 7600 series router and two Cisco 4404 Controllers that supports up to 300 lightweight access points. The router has eight internal Gigabit Ethernet ports that connect the router and the controller. The router and the internal controller run separate software versions, which must be upgraded separately.


Note The WiSM is supported on Cisco 7600 series routers running only Cisco IOS Release 12.2(18)SXF5 or later.



Note Without any other service module installed, the Cisco 7609 router chassis can support up to seven Cisco WiSMs, and any other Cisco 7600 series router chassis can support up to six Cisco WiSMs. If one or more service modules are installed, the chassis can support up to a maximum of four service modules (WiSMs included). Redundant supervisors cannot be used with these maximum configurations.



Note The Cisco WiSM controllers do not support port mirroring.


See the following documents for additional information:

Cisco 7600 Series Router Installation Guide

Cisco 7600 Series Router Software Configuration Guide

Cisco 7600 Series Router Command Reference

Configuring a Cisco Wireless Services Module and Wireless Control System

Catalyst 6500 Series Switch and Cisco 7600 Series Router Wireless Services Module Installation and Verification Note

You can find these documents at these URLs:

http://www.cisco.com/en/US/products/hw/routers/ps368/tsd_products_support_series_home.html

http://www.cisco.com/en/US/docs/wireless/technology/wism/technical/reference/appnote.html

http://www.cisco.com/en/US/docs/wireless/technology/wism/installation/note/78_17121.html

Cisco 28/37/38xx Series Integrated Services Router

The Cisco 28/37/38xx Series Integrated Services Router is an integrated 28/37/38xx router and Cisco controller network module that support up to 6, 8, 12, or 25 lightweight access points, depending on the version of the network module. The versions that support 8, 12, or 25 access points and the NME-AIR-WLC6-K9 6-access-point version feature a high-speed processor and more onboard memory than the NM-AIR-WLC6-K9 6-access-point version. An internal Fast Ethernet port (on the NM-AIR-WLC6-K9 6-access-point version) or an internal Gigabit Ethernet port (on the 8-, 12-, and 25-access-point versions and on the NME-AIR-WLC6-K9 6-access-point version) connects the router and the integrated controller. The router and the internal controller run separate software versions, which must be upgraded separately. See the following documents for additional information:

Cisco Wireless LAN Controller Network Module Feature Guide

Cisco 28/37/38xx Series Hardware Installation Guide

You can find these documents at this URL:

http://www.cisco.com/en/US/products/hw/wireless/index.html

Features Not Supported

These hardware feature are not supported on Cisco 28/37/38xx Series Integrated Services Routers:

Service port (separate out-of-band management 10/100-Mbps Ethernet interface)

Cisco 2100 Series Controller does not support the access point AP802.

These software features are not supported on Cisco 28/37/38xx Series Integrated Services Routers:

Bandwidth contracts

VPN termination (such as IPsec and L2TP)

VPN passthrough option

Termination of guest controller tunnels (origination of guest controller tunnels is supported)

External web authentication web server list

Spanning Tree Protocol (STP)

Port mirroring

AppleTalk

QoS per-user bandwidth contracts

IPv6 pass-through

Link aggregation (LAG)

Multicast-unicast mode

Port mirroring

Controller network module

Catalyst 3750G Integrated Wireless LAN Controller Switch

The Catalyst 3750G Integrated Wireless LAN Controller Switch is an integrated Catalyst 3750 switch and Cisco 4400 Series Controller that support up to 25 or 50 lightweight access points. The switch has two internal Gigabit Ethernet ports that connect the switch and the controller. The switch and the internal controller run separate software versions, which must be upgraded separately.


Note The controller in the Catalyst 3750G Integrated Wireless LAN Controller Switch does not support the Spanning Tree Protocol (STP).


See the following documents for additional information:

Catalyst 3750G Integrated Wireless LAN Controller Switch Getting Started Guide

Catalyst 3750 Switch Hardware Installation Guide

Release Notes for the Catalyst 3750 Integrated Wireless LAN Controller Switch, Cisco IOS Release 12.2(25)FZ

You can find these documents at this URL:

http://www.cisco.com/en/US/products/hw/switches/ps5023/tsd_products_support_series_home.html

Cisco UWN Solution Wired Connections

The Cisco UWN solution components communicate with each other using industry-standard Ethernet cables and connectors. Details of the wired connections are as follows:

The Cisco 2100 Series Controller connects to the network using from one to six 10/100BASE-T Ethernet cables.

The Cisco 4402 Controller connects to the network using one or two fiber-optic Gigabit Ethernet cables, and the Cisco 4404 Controller connects to the network using up to four fiber-optic Gigabit Ethernet cables.

The Cisco 5508 Controller connects to the network using up to eight fiber-optic Gigabit Ethernet cables.

The controllers in the Wireless Services Module (WiSM), installed in a Catalyst 6500 series switch or a Cisco 7600 series router, connect to the network through ports on the switch or router.

The Wireless LAN Controller Network Module, installed in a Cisco Integrated Services Router, connects to the network through the ports on the router.

The controller in the Catalyst 3750G Integrated Wireless LAN Controller Switch connects to the network through the ports on the switch.

Cisco lightweight access points connect to the network using 10/100BASE-T Ethernet cables. The standard CAT-5 cable can also be used to conduct power for the lightweight access points from a network device equipped with Power over Ethernet (PoE) capability. This power distribution plan can be used to reduce the cost of individual AP power supplies and related cabling.

Cisco UWN Solution WLANs

The Cisco UWN solution can control up to 512 WLANs for lightweight access points. Each WLAN has a separate WLAN ID (1 through 512), a separate profile name, and a WLAN SSID and can be assigned with unique security policies. The lightweight access points broadcast all active Cisco UWN solution WLAN SSIDs and enforce the policies defined for each WLAN.


Note Cisco 2106, 2112, and 2125 Controllers support only up to 16 WLANs.



Note We recommend that you assign one set of VLANs for WLANs and a different set of VLANs for management interfaces to ensure that controllers operate with optimum performance and ease of management.


If management over wireless is enabled across the Cisco UWN solution, you can manage the system across the enabled WLAN using CLI and Telnet, http/https, and SNMP.

To configure WLANs, see Chapter 7 "Configuring WLANs."

File Transfers

You can upload and download operating system code, configuration, and certificate files to and from the controller using the GUI, CLI, or Cisco WCS as follows:

To use the controller GUI or CLI, see Chapter 10 "Managing Controller Software and Configurations."

To use Cisco WCS to upgrade software, see the Cisco Wireless Control System Configuration Guide. Click this URL to browse to this document:

http://www.cisco.com/en/US/products/ps6305/products_installation_and_configuration_guides_list.html

Power Over Ethernet

Lightweight access points can receive power through their Ethernet cables from 802.3af-compatible Power over Ethernet (PoE) devices, which can reduce the cost of discrete power supplies, additional wiring, conduits, outlets, and installation time. PoE frees you from having to mount lightweight access points or other powered equipment near AC outlets, which provides greater flexibility in positioning the access points for maximum coverage.

When you are using PoE, you run a single CAT-5 cable from each lightweight access point to PoE-equipped network elements, such as a PoE power hub or a Cisco WLAN Solution single-line PoE injector. When the PoE equipment determines that the lightweight access point is PoE-enabled, it sends 48 VDC over the unused pairs in the Ethernet cable to power the access point.

The PoE cable length is limited by the 100BASE-T or 10BASE-T specification to 100 m or 200 m, respectively.

Lightweight access points can receive power from an 802.3af-compliant device or from the external power supply.

Cisco Wireless LAN Controller Memory

The controller contains two kinds of memory: volatile RAM, which holds the current, active controller configuration, and NVRAM (nonvolatile RAM), which holds the reboot configuration. When you are configuring the operating system in controller, you are modifying volatile RAM; you must save the configuration from the volatile RAM to the NVRAM to ensure that the controller reboots in the current configuration.

Knowing which memory you are modifying is important when you are doing the following tasks:

Using the configuration wizard

Clearing the controller configuration

Saving configurations

Resetting the controller

Logging out of the CLI

Cisco Wireless LAN Controller Failover Protection

During installation, we recommend that you connect all lightweight access points to a dedicated controller, and configure each lightweight access point for final operation. This step configures each lightweight access point for a primary, secondary, and tertiary controller and allows it to store the configured mobility group information.

During failover recovery, the following tasks are performed:

The configured access point attempts to contact the primary, secondary, and tertiary controllers, and then attempts to contact the IP addresses of the other controllers in the mobility group.

DNS is resolved with controller IP address.

DHCP servers get the controller IP Addresses (vendor specific option 43 in DHCP offer).

In multiple-controller deployments, if one controller fails, the access points perform the following tasks:

If the lightweight access point has a primary, secondary, and tertiary controller assigned, it attempts to associate with that controller.

If the access point has no primary, secondary, or tertiary controllers assigned or if its primary, secondary, or tertiary controllers are unavailable, it attempts to associate with a master controller.

If the access point finds no master controller, it attempts to contact stored mobility group members by the IP address.

If the mobility group members are available, and if the lightweight access point has no primary, secondary, and tertiary controllers assigned and there is no master controller active, it attempts to associate with the least-loaded controller to respond to its discovery messages.

When sufficient controllers are deployed, if one controller fails, active access point client sessions are momentarily dropped while the dropped access point associates with another controller, allowing the client device to immediately reassociate and reauthenticate.

To know more about high availability, see http://www.cisco.com/en/US/products/ps6366/products_tech_note09186a00809a3f5d.shtml

Network Connections to Cisco Wireless LAN Controllers

Regardless of the operating mode, all controllers use the network as an 802.11 distribution system. Regardless of the Ethernet port type or speed, each controller monitors and communicates with its related controllers across the network. The following sections give details of these network connections:

Cisco 2100 Series Wireless LAN Controllers

Cisco 4400 Series Wireless LAN Controllers

Cisco 5500 Series Wireless LAN Controllers


Note Chapter 3 "Configuring Ports and Interfaces" provides information on how to configure the controller's ports and how to assign interfaces to them.


Cisco 2100 Series Wireless LAN Controllers

Cisco 2100 Series Controller can communicate with the network through physical data ports, because the logical management interface can be assigned to ports. The physical port description is as follows:

Up to six 10/100BASE-T cables can plug into the six back-panel data ports on the Cisco 2100 series controller chassis. The Cisco 2100 series also has two PoE ports (ports 7 and 8).

Figure 1-4 shows connections to the Cisco 2100 Series Controller.

Figure 1-4 Physical Network Connections to the Cisco 2100 Series Controller

Cisco 4400 Series Wireless LAN Controllers

Cisco 4400 Series Controllers can communicate with the network through two pairs of physical data ports, and the logical management interface can be assigned to the ports.

For the Cisco 4402 Controller, up to two of the following connections are supported in any combination:

1000BASE-T (Gigabit Ethernet, front panel, RJ-45 physical port, UTP cable).

1000BASE-SX (Gigabit Ethernet, front panel, LC physical port, multimode 850nM (SX) fiber-optic links using LC physical connectors).

1000BASE-LX (Gigabit Ethernet, front panel, LC physical port, multimode 1300nM (LX/LH) fiber-optic links using LC physical connectors).

For the Cisco ontroller, up to four of the following connections are supported in any combination:

1000BASE-T (Gigabit Ethernet, front panel, RJ-45 physical port, UTP cable).

1000BASE-SX (Gigabit Ethernet, front panel, LC physical port, multi-mode 850nM (SX) fiber-optic links using LC physical connectors).

1000BASE-LX (Gigabit Ethernet, front panel, LX physical port, multi-mode 1300nM (LX/LH) fiber-optic links using LC physical connectors).

Figure 1-5 shows connections to the Cisco 4400 Series Controller.

Figure 1-5 Physical Network Connections to Cisco 4402 and 4404 Controllers

Cisco 5500 Series Wireless LAN Controllers

Cisco 5500 Series Controllers can communicate with the network through up to eight physical data ports, and the logical management interface can be assigned to the ports.

For the Cisco Controller, up to eight of the following connections are supported in any combination:

1000BASE-T (Gigabit Ethernet, front panel, RJ-45 physical port, UTP cable).

1000BASE-SX (Gigabit Ethernet, front panel, LC physical port, multi-mode 850nM (SX) fiber-optic links using LC physical connectors).

1000BASE-LX (Gigabit Ethernet, front panel, LX physical port, multi-mode 1300nM (LX/LH) fiber-optic links using LC physical connectors).